CN100422814C - Backlight module - Google Patents

Abstract

The invention discloses a backlight module, which comprises a reflecting plate and a light source. The reflecting plate is provided with a plurality of reflecting areas, the light source is arranged on at least one side of the reflecting plate, and the emitted light is reflected by the reflecting plate and emitted towards a light emitting side. The diffusion rate of the reflection area far away from the light source in the reflection area is different from that of the reflection area close to the light source.

Description

Backlight module

technical field

The invention relates to a backlight module, in particular to a backlight module with reflection plates with different diffusivity.

Background technique

The liquid crystal display device mainly uses a liquid crystal panel (LCD panel) to display. Since the liquid crystal panel itself does not emit light, it is necessary to supply a light source with sufficient brightness and uniform distribution so that the liquid crystal panel can display images normally. This function of supplying light is performed by a backlight module. The backlight module can be divided into two types according to different structures: an edge-lit backlight module and a direct-lit backlight module.

In the design of the direct-type backlight module, the light tube as the light source is placed directly under the backlight module. Because the installation space becomes larger, more than two light tubes can be used to increase the light intensity, but it also increases the backlight module. Thickness and power consumption of the lamp tube, so it is more suitable for general liquid crystal displays that are less critical to portability and space requirements; while edge-lit backlight modules usually use a single lamp tube or multiple lamp tubes placed on the light guide plate The side of the light source can be used as a light source, and the design of the light guide plate can be used to strengthen the control of the direction of light travel.

Referring to FIG. 1 , the structure of an existing edge-lit backlight module is described. FIG. 1 shows an exploded view of a liquid crystal display device 100 using a conventional edge-lit backlight module. The liquid crystal display device 100 has a liquid crystal panel 180 , a frame 190 , and an edge-lit backlight module wrapped inside the frame 190 . The edge-lit backlight module includes a lamp tube as a light source 110, a reflector 120, a light guide plate 130, and other optical films 140 suitable for backlight modules, such as protective diffusion sheets, prism sheets, light collection sheets, In addition, a light source reflection sheet 115 may be provided outside the light source 110 to prevent the light emitted by the light source 110 from being scattered outside the backlight module. The light guide plate 130 and other optical films 140 can be increased or decreased according to the requirements of the backlight module.

As shown in Figure 1, the light source 110 of the edge-lit backlight module directs the light to the light guide plate 130, and the light guide plate 130 guides the scattering direction of the light, so that the light is directed to the light-emitting side (ie, the direction of the liquid crystal panel 180), so as to improve the liquid crystal display. The display luminance of the device 100 is ensured and the uniformity of the luminance of the liquid crystal panel 180 is ensured. The function of the reflector 120 is to reflect the light that exits the light guide plate 130 but not toward the light exit side back into the light guide plate 130 so that it is directed toward the light exit side, so as to improve light utilization efficiency. In an edge-lit backlight module that does not use the light guide plate 130 , the light emitted by the light source 110 is directly reflected by the reflector 120 and then directed toward the light emitting side.

Generally speaking, the luminance and uniformity of the edge-lit backlight module will vary depending on the microstructure and size of the light guide plate. However, in the existing edge-lit backlight modules, if a light guide plate is used for light guide, the light incident efficiency will be reduced; and when the size of the backlight is large, the weight of the light guide plate will increase a lot. However, the reflector 120 is mostly made of a single material. When the structure or size of the edge-lit backlight module changes, this single-material reflector 120 cannot produce corresponding reflection characteristics in response to different specifications of various edge-lit backlight modules. Adjustment, so it is prone to the problem of poor brightness uniformity.

In addition, the light source 110 used in the edge-lit backlight module, in addition to the difference in its own characteristics, the different positions of the light source 110 will also cause the luminance to change. For example, the light source 110 may be arranged on one side of the reflector 120 as shown in FIG. 2A , may also be arranged on opposite sides of the reflector 120 as shown in FIG. on the periphery of the reflector 120 . The reflective plate 120 made of a single material cannot adjust the corresponding reflective characteristics in response to different configurations of various light sources, so the problem of poor brightness uniformity is likely to occur.

Contents of the invention

In view of this, an embodiment of the present invention discloses a backlight module for a liquid crystal display device, the backlight module includes a reflector and a light source. There are multiple reflective areas on the reflective plate, and the light source is arranged on at least one side of the reflective plate. Wherein, the surface of the reflection area farther away from the light source is a diffusion surface, and the surface of the reflection area closer to the light source is a mirror surface, so that the diffusivity of the reflection area farther away from the light source is higher than that of the reflection area closer to the light source. the diffusion rate.

Another embodiment of the present invention discloses a backlight module for a liquid crystal display device, the backlight module includes a reflective plate with a first reflective area located on both sides and a second reflective area located in the center, wherein the The surface of the second reflection area is a diffusion surface, and the surface of each first reflection area is a mirror surface, so that the diffusivity of the second reflection area is different from the diffusivity of the first reflection area; and two light sources are respectively arranged on the reflection plate The side, close to the first reflective area.

Another embodiment of the present invention discloses a backlight module for a liquid crystal display device. The backlight module includes a reflective plate with a first reflective area surrounding the outer side and a second reflective area located inside. , wherein the surface materials of the first reflective area and the second reflective area are different, so that the diffusivity of the second reflective area is different from the diffusivity of the first reflective area; and at least one light source is arranged around the outer side of the reflective plate The edge is close to the first reflective area, wherein the surface of the second reflective area is a diffuse surface, and the surface of the first reflective area is a specular surface.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, specific preferred embodiments are specifically cited below and described in detail in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a side exploded view of an existing edge-lit backlight module;

2A is a schematic diagram of a light source arranged on one side of a reflector in an existing edge-lit backlight module;

FIG. 2B is a schematic diagram of light sources arranged on both sides of a reflector in an existing edge-lit backlight module;

FIG. 2C is a schematic diagram of a light source ring disposed around a reflector in an existing edge-lit backlight module;

3 is an exploded perspective view of a backlight module according to an embodiment of the present invention;

4A is a schematic diagram of a backlight module according to another embodiment of the present invention;

FIG. 4B is a schematic diagram of a backlight module according to another embodiment of the present invention; and

FIG. 4C is a schematic diagram of a backlight module according to another embodiment of the present invention.

Detailed ways

Please refer to FIG. 3 , which illustrates the structure of a backlight module according to an embodiment of the present invention. The backlight module shown in FIG. 3 is a type in which the light source 10 is arranged on both sides of the reflector 20. In addition to the light source 10 and the reflector 20, its structure also has an optical film 40 and a light source reflector 15, but does not have a light guide plate. The light source 10 is disposed on both sides of the reflection plate 20, and the reflection plate 20 has a plurality of reflection areas 20a, 20b, 20c, 20d, 20e, 20f, 20g defined according to the light source. The light emitted by the light source 10 is reflected by the reflector 20 and then directly exits toward the light emitting side (ie, toward the direction of the optical film 40 ). Among them, among the reflection areas 20a, 20b, 20c, 20d, 20e, 20f, and 20g, the reflection area farther away from the light source 10 is the most central reflection area 20d, and the reflection area closer to the light source 10 is the reflection area near the two sides. 20a and 20g. In order to improve the brightness uniformity of the backlight module, the diffusivity of the reflective regions 20a, 20b, 20c, 20d, 20e, 20f, and 20g are different from each other, and the reflective region 20d farther away from the light source 10 has the highest diffusivity (such as surface is the diffusion surface); and the reflective regions 20a and 20g closer to the light source have the lowest diffusivity (for example, the surface is a mirror surface), and the reflective regions in the middle are adjusted according to the distance from the light source 10, and the farther the distance is, the higher the diffusivity is. .

The reflective regions 20a, 20b, 20c, 20d, 20e, 20f, and 20g of the above-mentioned reflector 20 can directly adopt different surface materials when manufacturing the reflector 20, so as to achieve the effect of different diffusivity, or manufacture the same material first. After the reflective plate 20, different concentrations of diffusing particles are coated on the surface of different reflective areas, so as to achieve the effect of different diffusivity. For example, more diffusing particles can be coated on the surface of the reflective region farther away from the light source, so that the concentration of diffusing particles on the surface of the reflective region farther away from the light source is greater than that of the surface of the reflective region closer to the light source.

Furthermore, for different configurations of the light sources 10 used in the backlight module, the reflection areas on the reflection plate 20 also have different configurations. Referring to FIG. 4A , FIG. 4B and FIG. 4C , the configuration of the reflective area on the reflective plate 20 will be described for different configurations of the light source 10 .

In the embodiment of FIG. 4A , the light source 10 is disposed on one side of the reflector 20 . At this time, the reflective area on the reflective plate 20 can be divided into a first reflective area 201 close to the light source 10, a second reflective area 202 far away from the light source 10, and a second reflective area between the first reflective area 201 and the second reflective area 202. Three reflection areas 203 . The first reflective region 201 has a first diffusivity, the second reflective region 202 has a second diffusivity, and the third reflective region 203 has a third diffusivity. Since the second reflective region 202 is furthest away from the light source 10, its second diffusivity is higher than the third diffusivity of the third reflective region 203, and the third diffusivity of the third reflective region 203 is higher than that of the first reflective region 201. first diffusivity. In this way, the brightness uniformity of the backlight module can be improved.

In the embodiment of FIG. 4B , two light sources 10 are respectively disposed on two sides of the reflective plate 20 . At this time, the reflective area on the reflective plate 20 can be divided into the first reflective area 201 located on both sides and closest to the light source 10, the second reflective area 202 located in the center and farthest from the light source 10, and the second reflective area 202 located in the first reflective area. 201 and the third reflective area 203 between the second reflective area 202 . The first reflective region 201 has a first diffusivity, the second reflective region 202 has a second diffusivity, and the third reflective region 203 has a third diffusivity. Since the second reflective region 202 is furthest away from the light source 10, its second diffusivity is higher than the third diffusivity of the third reflective region 203, and the third diffusivity of the third reflective region 203 is higher than that of the first reflective region 201. first diffusivity. In this way, the brightness uniformity of the backlight module can be improved.

In the embodiment shown in FIG. 4C , a plurality of light sources 10 are respectively arranged around the periphery of the reflection plate 20 (ie, all outer sides). At this time, the reflective area on the reflector 20 can be divided into a first reflective area 201 that is located on the outermost side and is closest to the light source 10, a second reflective area 202 that is located inside and is farthest from the light source 10, and a second reflective area 202 that is located on the outermost side and is closest to the light source 10. The third reflective area 203 between the first reflective area 201 and the second reflective area 202 . The first reflective region 201 has a first diffusivity, the second reflective region 202 has a second diffusivity, and the third reflective region 203 has a third diffusivity. Since the second reflective region 202 is farthest from the light source 10, its second diffusivity is higher than the third diffusivity of the third reflective region 203, and the third diffusivity of the third reflective region 203 is higher than that of the first reflective region 201. first diffusivity. In this way, the brightness uniformity of the backlight module can be improved.

It must be explained here that the above-mentioned embodiments in FIGS. 4A-4C divide the reflective areas into three groups. However, in practical applications, the reflective areas can be divided into any number of combinations according to the structure and size requirements of the backlight module. Limited by the above embodiments.

In addition, in the above-mentioned embodiments, the light source can be a CCFL or a light-emitting diode (LED), and other luminous bodies suitable as the light source for the backlight module can also be used.

Although the present invention has been disclosed in combination with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can still make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention should be defined by the claims.

Claims (10)

1. a backlight module is used for liquid crystal indicator, and this backlight module comprises:

One reflecting plate has a plurality of reflector spaces; And

At least one light source is arranged at least one side of this reflecting plate;

Wherein, the surface away from the reflector space of this light source is a diffusingsurface, the surface near the reflector space of this light source is a minute surface, so that be higher than diffusivity near the reflector space of this light source away from the diffusivity of the reflector space of this light source in this each reflector space.

2. backlight module as claimed in claim 1, wherein this light source is cathode fluorescent tube or light emitting diode.

3. backlight module as claimed in claim 1, wherein this reflecting plate comprises:

One first reflector space adjacent to this light source, has one first diffusivity;

One second reflector space is away from this light source, has one second diffusivity; And

One the 3rd reflector space between this first reflector space and this second reflector space, has one the 3rd diffusivity,

Wherein this second diffusivity is greater than the 3rd diffusivity, and the 3rd diffusivity is greater than this first diffusivity.

4. a backlight module is used for liquid crystal indicator, and this backlight module comprises:

One reflecting plate, one second reflector space that has first reflector space that is positioned at dual-side and be positioned at central portion, wherein the surface of this second reflector space is a diffusingsurface, respectively the surface of first reflector space is a minute surface, so that the diffusivity of this second reflector space is different from the diffusivity of this each first reflector space; And

Two light sources are arranged at this each side of this reflecting plate respectively, near should each first reflector space.

5. backlight module as claimed in claim 4, wherein this each light source is cathode fluorescent tube or light emitting diode.

6. backlight module as claimed in claim 4, wherein this reflecting plate also comprises one the 3rd reflector space, be arranged between this first reflector space and this second reflector space, the diffusivity of the 3rd reflector space is higher than the diffusivity of this each first reflector space, and is lower than the diffusivity of this second reflector space.

7. a backlight module is used for liquid crystal indicator, and this backlight module comprises:

One reflecting plate, have one first reflector space of the outer side edges of being located on and be located at one second inner reflector space, wherein this first reflector space is different with the Facing material of this second reflector space, so that the diffusivity of this second reflector space is different from the diffusivity of this first reflector space; And

At least one light source is located on this each outer side edges of this reflecting plate, near this first reflector space,

Wherein the surface of this second reflector space is a diffusingsurface, and the surface of this first reflector space is a minute surface.

8. backlight module as claimed in claim 7, wherein the diffusivity of this second reflector space is higher than the diffusivity of this each first reflector space.

9. backlight module as claimed in claim 7, wherein this reflecting plate also has the 3rd reflector space, be located between this first reflector space and this second reflector space, the diffusivity of the 3rd reflector space is higher than the diffusivity of this first reflector space, and is lower than the diffusivity of this second reflector space.

10. backlight module as claimed in claim 7, wherein this light source is cathode fluorescent tube or light emitting diode.

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