CN1542513A - Backlight module - Google Patents

Abstract

A backlight module comprises a light guide plate, a side light source and a bottom light source. The side light source is arranged beside the side face of the light guide plate, the bottom light source is arranged on the bottom face of the light guide plate, light rays provided by the side light source and the bottom light source can be emitted from the top face of the light guide plate, and a high-brightness surface light source can be provided by the side light source and the bottom light source, so that the display effect of the liquid crystal display is improved. In addition, the invention also provides a liquid crystal display which is mainly composed of a penetration type or semi-penetration and semi-reflection type liquid crystal panel and the backlight module.

Description

Backlight module

technical field

The invention relates to a backlight module (Back Light Module) and a liquid crystal display (Liquid Crystal Display, LCD), and in particular to a backlight module and a liquid crystal display capable of providing a surface light source with high brightness.

Background technique

The rapid progress of the multimedia society is mostly due to the rapid progress of semiconductor components or man-machine display devices. As far as the display is concerned, the cathode ray tube (Cathode Ray Tube, CRT) has been monopolizing the display market in recent years because of its excellent display quality and economy. However, for the environment where individuals operate most terminals/display devices on the table, or from the viewpoint of environmental protection, if the trend of energy saving is predicted, cathode ray tubes still have many problems in terms of space utilization and energy consumption, and There is no effective solution to the demands of lightness, thinness, shortness, smallness and low power consumption. Therefore, liquid crystal displays with superior characteristics such as high image quality, space utilization efficiency, low power consumption, and no radiation have gradually become the mainstream of the market.

FIG. 1 shows a schematic diagram of a conventional liquid crystal display. Please refer to FIG. 1 , the liquid crystal display 100 is mainly composed of a liquid crystal panel 110 and a backlight module 120 . Wherein, the backlight module 120 is disposed at the back of the liquid crystal panel 110, the back is relative to the user, and the backlight module 120 is formed by a light guide plate 122, a side light source 124, a reflector 126 and a frame (frame) 128. constitute.

The light guide plate 122 is, for example, a wedge-shaped light guide plate. The light guide plate 122 has a top surface 130, a bottom surface 132 and a side surface 134, wherein the top surface 130 of the light guide plate 122 is designed as a light-emitting surface, and the bottom surface 132 of the light guide plate 122 is designed as The side surface 134 of the light guide plate 122 is designed as a light incident surface.

The side light source 124, such as a cold cathode fluorescent tube (Cold Cathode Fluorescence Lamp, CCFL), is arranged beside the side 134 of the light guide plate 122, and the light provided by the side light source 124 can enter the light guide plate 122 through the side 134, and After being scattered and reflected by the bottom surface 132 , it is transmitted to the top surface 130 and emitted. It can be seen from the above that the light emitted from the top surface 130 is a type of surface light source.

The reflector 126 is arranged beside the side surface 134 of the light guide plate 122 and covers the side light source 124 . In addition, the frame 128 is used to carry the above-mentioned light guide plate 122 , side light source 124 and reflector 126 , so that the light guide plate 122 , side light source 124 and reflector 126 can be integrated.

As mentioned above, since the liquid crystal molecules themselves do not emit light, the surface light source required by the liquid crystal panel 110 must be provided by the backlight module 120 so that the liquid crystal panel 110 can achieve the display effect and obtain sufficient brightness and contrast.

Since the current liquid crystal display has moved from XGA to a higher resolution, under the limitation of high resolution, because the transmittance of the liquid crystal panel cannot be further improved, it is bound to effectively increase the brightness of light to meet the high brightness of the liquid crystal display. degree of demand. Among the existing methods for increasing the light intensity of liquid crystal displays, the most common method is to increase the brightness of the side light source. Since the side light source is mostly cold-cathode lamp (CCFL), it can only be achieved by increasing the tube current. Increase the brightness of the surface of the lamp tube, but the scope of its brightness improvement is still very limited. The increase of the tube current will greatly increase the power consumed by the backlight module, and at the same time, the service life of the lamp tube in the module will also be greatly shortened.

In addition, the method for increasing the light intensity of the existing liquid crystal display also includes increasing the number of lamp tubes, but while increasing the number of lamp tubes, not only the overall power consumption is greatly increased, but also the thickness and weight of the backlight module It is also bound to increase, and such a design does not conform to the development trend of light, thin, short, and small liquid crystal displays. In addition, after increasing the number of lamps, it is necessary to design an inverter for driving the multiple lamps, and it is difficult to protect against electromagnetic interference (EMI) generated by the multiple lamps.

Contents of the invention

Therefore, the object of the present invention is to provide a backlight module, which improves the overall luminance and adjustable luminance range of the backlight module by adding a bottom light source to match the originally designed side light source.

Another object of the present invention is to provide a backlight module, which increases its service life by adding a bottom light source to match the originally designed side light source.

Another object of the present invention is to provide a liquid crystal display, which not only has high-brightness and high-resolution display capabilities, but can still meet the demand for miniaturization.

Based on the above purpose, the present invention provides a backlight module suitable for providing a side light source. The backlight module is composed of a light guide plate, a side light source and a bottom light source. Wherein, the light guide plate has a top surface, a bottom surface and at least one side surface. The side light source is arranged beside the side of the light guide plate, and the light provided by the side light source can enter the light guide plate from the side of the light guide plate, pass through the bottom surface of the light guide plate, and then transmit to the top surface of the light guide plate to exit. The bottom light source is arranged on the bottom surface of the light guide plate, and the light provided by the bottom light source can enter the light guide plate from the bottom surface of the light guide plate and exit from the top surface of the light guide plate.

Based on the above purpose, the present invention also provides a liquid crystal display, which is composed of a liquid crystal panel and a backlight module. Wherein, the backlight module is composed of a light guide plate, a side light source and a bottom light source. The light guide plate has a top surface, a bottom surface and at least one side surface. The side light source is arranged beside the side of the light guide plate, and the light provided by the side light source can enter the light guide plate from the side of the light guide plate, pass through the bottom surface of the light guide plate, and then transmit to the top surface of the light guide plate to exit. The bottom light source is arranged on the bottom surface of the light guide plate, and the light provided by the bottom light source can enter the light guide plate from the bottom surface of the light guide plate and exit from the top surface of the light guide plate.

According to the preferred embodiment of the present invention, the shape of the light guide plate can be wedge-shaped, and its bottom surface can be made into a stepped surface or its bottom surface can be designed with multiple concave points to scatter the light provided by the side light source , and the side light source can be a cold cathode lamp.

According to the preferred embodiment of the present invention, the bottom light source can be an organic electroluminescence component, and the organic electroluminescence component is composed of a transparent substrate, an anode, an organic functional layer and a cathode. Wherein, the anode is formed on the transparent substrate, the organic functional layer is formed on the anode, and the cathode is formed on the organic functional layer.

Wherein, the organic functional layer is sequentially composed of a hole injection layer, a hole conduction layer, an organic light emitting layer and an electron conduction layer. Wherein, the hole injection layer is formed on the anode, the hole conduction layer is formed on the hole injection layer, the organic light-emitting layer is formed on the hole conduction layer, and the electron conduction layer is formed between the organic light-emitting layer and the cathode. .

In addition, the above-mentioned organic electroluminescent component is directly formed on the transparent substrate, however, the organic electroluminescent component of the present invention can also be directly formed on the bottom surface of the light guide plate. In this embodiment, when the organic electroluminescence component is fabricated on the bottom surface of the light guide plate, it is only necessary to form a flat layer on the bottom surface of the light guide plate to provide a flat surface, and then fabricate the organic electroluminescent component on the flat layer. each film layer.

According to the preferred embodiment of the present invention, in order to increase the luminance presentation of the backlight module and the display capability of the liquid crystal display, a diffusion sheet and a brightness enhancement sheet can be arranged on the light-emitting surface of the light guide plate, or a Reflector to cover side light sources.

According to the preferred embodiment of the present invention, in order to integrate the light guide plate, side light source, bottom light source and reflector in the backlight module, for example, a frame can be used to carry the main light plate, side light source, bottom light source and reflector.

According to the preferred embodiment of the present invention, the liquid crystal display is, for example, a transmissive panel or a semi-transmissive and semi-reflective liquid crystal panel.

As mentioned above, the present invention additionally configures a bottom light source on the bottom surface of the light guide plate, which can be used in conjunction with the originally designed side light source. By adding the side light source and the bottom light source of the backlight module, a high-brightness surface light source can be provided. , and can further prolong the service life of the backlight module. In this way, the liquid crystal display can not only meet the requirements of high brightness and high resolution, but also maintain the characteristics of lightness, thinness, shortness and smallness.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment will be described in detail below together with the accompanying drawings.

Description of drawings

FIG. 1 shows a schematic diagram of an existing liquid crystal display;

Figure 2 shows a schematic diagram of a liquid crystal display according to a preferred embodiment of the present invention; and

FIG. 3 shows an enlarged schematic cross-sectional view of the area A in FIG. 2 , which especially shows the structure of the bottom light source.

Explanation of reference signs

100 LCD display 110 LCD panel

120 Backlight module 122 Light guide plate

124 side light source 126 reflector

128 Frame 130 Top

132 Bottom 134 Side

200 LCD display 210 LCD panel

220 Backlight module 222 Light guide plate

224 side light source 226 reflector

228 Frame 230 Diffuser

232 Enhancement film 234 Bottom light source

236 top surface 238 bottom surface

240 side 242 transparent substrate

244 Anode 246 Organic functional layer

246a Hole Injection Layer 246b Hole Conduction Layer

246c organic light-emitting layer 246d electron conducting layer

248 Cathode

Detailed ways

FIG. 2 shows a schematic diagram of a liquid crystal display according to a preferred embodiment of the present invention. Please refer to FIG. 2 , the liquid crystal display 200 is mainly composed of a liquid crystal panel 210 and a backlight module 220 . Wherein, the liquid crystal panel 210 may be a transmissive or transflective liquid crystal panel, and the backlight module 220 is disposed on the back side of the liquid crystal panel 210. The backlight module 220 is composed of a light guide plate 222, The side light source 224 , the reflector 226 , the frame 228 , the diffusion sheet 230 , the enhancement sheet 232 and the bottom light source 234 are formed.

Wherein, the shape of the light guide plate 222 can be made into a wedge shape, and the light guide plate 222 has a top surface 236, a bottom surface 238 and a side surface 240, wherein the top surface 236 is designed as a light emitting surface, the bottom surface 238 is designed as a scattering surface, and the side surface 240 Designed as a light incident surface. In addition, the bottom surface 238 can be designed as a stepped surface (as shown in FIG. 3 ) or has a plurality of concave points (not shown in the figure), so as to scatter the light provided by the side light source 224 .

The side light source 224, which may be a cold cathode fluorescent tube (CCFL), is arranged beside the side 240 of the light guide plate 222, and the light provided by the side light source 224 can enter the light guide plate 222 from the side 240 and be scattered by the bottom surface 238 , passed to the top surface 236 to exit. It can be seen from the above that the light emitted from the top surface 236 is a type of surface light source.

The reflector 226 is disposed next to the side 240 of the light guide plate 222 and covers the side light source 224. The light provided by the side light source 224 can be irradiated in a direction toward the side 240 of the light guide plate 222 through the reflection of the reflector 226. . The diffusion sheet 230 is arranged on the top surface 236 of the light guide plate 222, and the brightness enhancement sheet 232 is arranged on the diffusion sheet 230, and the luminance presentation and brightness of the backlight module 200 are increased by the reflector 226, the diffusion sheet 230 and the brightness enhancement sheet 232. LCD display capabilities. In addition, the frame 228 can carry the light guide plate 222, the side light source 224, the bottom light source 234 and the reflector 226, so that the light guide plate 222, the side light source 224, the bottom light source 234 and the reflector 226 can be integrated.

FIG. 3 shows an enlarged schematic cross-sectional view of the area A in FIG. 2 , which especially shows the structure of the bottom light source. Please refer to FIG. 3 , in this embodiment, the bottom light source 234 is an organic electroluminescent component, which is composed of a transparent substrate 242 , an anode 244 , an organic functional layer 246 and a cathode 248 . Wherein, the transparent substrate 242 is formed on the bottom surface 238 of the light guide plate 222 , the anode 244 is formed on the transparent substrate 242 , the organic functional layer 246 is formed on the anode 244 , and the cathode 248 is formed on the organic functional layer 246 .

In addition, the organic functional layer is composed of a hole injection layer 246a, a hole conduction layer 246b, an organic light emitting layer 246c and an electron conduction layer 246d. Wherein, the hole injection layer 246a is formed on the anode 244, the hole conduction layer 246b is formed on the hole injection layer 246a, the organic light-emitting layer 246c is formed on the hole conduction layer 246d, and the electron conduction layer 246d is formed on the Between the organic light emitting layer 246c and the cathode 248 .

However, in another embodiment, the organic electroluminescence component can also be directly formed on the bottom surface 238 of the light guide plate 222 . The method is to form an organic electroluminescence component on the bottom surface 238 of the light guide plate 222, only need to form a flat layer (not shown) on the bottom surface 238 of the light guide plate 222 to provide a flat surface, and then on the flat layer All the film layers required for the fabrication of the organic electroluminescent component are sufficient.

Please refer to FIG. 2 and FIG. 3 together. By providing a current to drive the bottom light source 234 to emit light, the light provided by the bottom light source 234 can enter the light guide plate 222 from the bottom surface 238 of the light guide plate 222, and be transmitted by the light guide plate 222. The top surface 236 is emitted, and the light emitted from the top surface 236 is also a type of surface light source. When using the liquid crystal display 200, the side light source 224 and the bottom light source 234 can be driven at the same time, and a high-brightness surface light source is provided by the addition of the two light sources, so that the liquid crystal panel 210 can obtain sufficient brightness and achieve the best display Effect. Of course, in the case of low brightness requirements, the side light source 224 and the bottom light source 234 can also be selected to be used separately, which can prolong the service life of the backlight module 200 .

Based on the above, the backlight module and liquid crystal display of the present invention have at least the following advantages:

1. The backlight module of the present invention can provide a high-brightness surface light source by adding the side light source and the bottom light source, so as to improve the overall luminance and adjustable luminance range of the backlight module, so that the liquid crystal display can meet high brightness, high resolution requirements.

2. In the backlight module of the present invention, the side light source and the bottom light source can be used together or individually, thereby prolonging the service life of the backlight module.

3. The backlight module of the present invention, wherein the bottom light source is arranged on the bottom surface of the light guide plate, does not greatly increase the overall volume of the backlight module, so that the liquid crystal display can still maintain the characteristics of being light, thin and short.

Although the present invention has been disclosed above in conjunction with a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection of the invention is defined by the claims.

Claims (9)

1. backlight module comprises at least:

One light guide plate has an end face, a bottom surface and at least one side;

One sidelight source is configured in by this side of this light guide plate, and wherein the light that provided of this sidelight source can be by this this light guide plate of side incident, and via being passed to this end face outgoing behind this bottom surface; And

One bottom light source is configured on this bottom surface of this light guide plate, and wherein the light that this bottom light source provided can be via this this light guide plate of bottom surface incident, and by this end face outgoing.

2. backlight module as claimed in claim 1, wherein this light guide plate is a wedge shape light guide plate.

3. backlight module as claimed in claim 1, wherein this bottom surface of this light guide plate is a step-like surface or has a plurality of concave points, is used for light scatter that this sidelight source is provided.

4. backlight module as claimed in claim 1, wherein this sidelight source is a cold cathode fluorescent lamp.

5. backlight module as claimed in claim 1, wherein this bottom light source is an organic EL component.

6. backlight module as claimed in claim 5, wherein this organic EL component comprises:

One transparent base;

One anode is formed on this transparent base;

One organic functional layer is formed on this anode; And

One negative electrode is formed on this organic functional layer.

7. backlight module as claimed in claim 6, wherein this organic functional layer comprises:

One hole injection layer is formed on this anode;

One hole-conductive layer is formed on this hole injection layer;

One organic luminous layer is formed on this hole-conductive layer: and

One electronic conductive layer is formed between this organic luminous layer and this negative electrode.

8. backlight module as claimed in claim 5, wherein this organic EL component comprises:

One flatness layer is formed on this bottom surface of this light guide plate;

One anode is formed on this flatness layer;

One organic functional layer is formed on this anode; And

One negative electrode is formed on this organic functional layer.

9. backlight module as claimed in claim 8, wherein this organic functional layer comprises:

One hole injection layer is formed on this anode;

One hole-conductive layer is formed on this hole injection layer;

One organic luminous layer is formed on this hole-conductive layer: and

One electronic conductive layer is formed between this organic luminous layer and this negative electrode.

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