CN101576683A - Display device - Google Patents

Abstract

The present invention provides a display device including: a liquid crystal display panel; and a backlight module set under the liquid crystal display module, wherein the backlight module at least comprises: a light guide plate; a light splitting layer arranged on the light guide plate, wherein the light splitting layer is provided with a plurality of microstructures; a first light source disposed on a first side of the light guide plate; and a second light source disposed at a second side of the light guide plate.

Description

display device

technical field

The present invention relates to a backlight module and its application, and in particular to a backlight module capable of providing backlight in different viewing angle ranges and its application on a display device.

Background technique

With the continuous innovation of the information and communication industries, the liquid crystal display (Liquid Crystal Display; LCD) market is booming. Liquid crystal displays have the advantages of high image quality, small size, light weight, low driving voltage, and low power consumption, so they are widely used in personal digital assistants (Personal Digital Assistant; PDA), mobile phones, camcorders, notebooks, etc. Consumer communication or electronic products such as computers, desktop monitors, car monitors, and projection TVs. Coupled with the rapid development of integrated circuit (Integrated Circuit; IC) industry and liquid crystal display manufacturing technology, these consumer communication or electronic products are also developing towards the trend of light, thin, short and small. Especially in terms of computer products, in addition to high-performance, high-speed desktop computers, portable notebook computers have received great attention and attention.

In general liquid crystal display devices, the light emitting direction of the backlight source is mostly fixed, and the distribution of the light type (light emitting angle) is maintained in a certain range, so general liquid crystal display devices can only be viewed within a specific viewing angle range. . Taking car panels as an example, the automotive industry has gradually improved in-car entertainment functions, and car navigation systems and DVD audio-visual systems have become the basic equipment in many cars. However, when the car navigation system and the DVD audio-visual system are used at the same time, two display devices need to be installed in the car, thus increasing the installation cost and reducing the configuration space in the car.

Please refer to FIG. 1 , which shows a schematic structural diagram of a conventional liquid crystal display device. The known liquid crystal display device uses a "parallax barrier" method to display images in two directions at the same time, so as to achieve the dual view (Dual View) simultaneous display effect. It is set on the liquid crystal display module 920 through a color filter (Color Filter) 910 with a barrier photomask to separate the light of different images from emitting in two directions, so that it can be viewed from two directions at the same time Images A and B.

However, the process of the color filter 910 with the barrier photomask is complicated and difficult, thus increasing the process cost and difficulty of realizing Dual View.

Contents of the invention

Therefore, one aspect of the present invention is to provide a backlight module for providing backlights for different viewing angles.

Yet another aspect of the present invention is to provide a backlight module and its application on a display device, so as to simultaneously display different images in different viewing angle ranges.

According to an embodiment of the present invention, the backlight module of the present invention at least includes a light guide plate, a light splitting layer, a first light source and a second light source. The light-splitting layer is arranged on the light guide plate, wherein the light-splitting layer is provided with a plurality of microstructures. The first light source is arranged on the first side of the light guide plate. The second light source is arranged on the second side of the light guide plate.

Moreover, according to an embodiment of the present invention, the above-mentioned backlight module at least includes a gap layer, which is formed between the light guide plate and the light splitting layer, wherein the light refractive index of the gap layer is substantially smaller than the light refractive index and light splitting layer of the light guide plate, respectively. The light refraction index of the layer, and the light refraction index of the light guide plate is substantially the same as the light refraction index of the light splitting layer.

Moreover, according to the embodiments of the present invention, the backlight module of the present invention can be applied to a liquid crystal display device.

Therefore, the backlight module of the present invention can provide backlight toward different viewing angle ranges, and thus the liquid crystal display device applied to the backlight module of the present invention can simultaneously display different picture images toward different viewing angle ranges to achieve dual viewing angles ( Dual View) can be displayed at the same time.

Description of drawings

In order to make the above and other objects, features, advantages and embodiments of the present invention more obvious and understandable, the detailed description of the accompanying drawings is as follows:

FIG. 1 is a schematic diagram illustrating the structure of a conventional liquid crystal display device.

2 is a schematic cross-sectional view illustrating a backlight module and a liquid crystal display module according to a first embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating the structure of the light uniform module of the backlight module according to the first embodiment of the present invention.

FIG. 4 is a perspective view illustrating a partial light-splitting layer according to a first embodiment of the present invention.

FIG. 5 is a schematic perspective view illustrating a light splitting layer according to a second embodiment of the present invention.

6 is a schematic cross-sectional view illustrating a light guide plate and a light splitting layer according to a third embodiment of the present invention.

[Description of main component symbols]

A, B: video

a: The range of the first viewing angle b: The range of the second viewing angle

n ₁ , n ₂ , n ₃ , n ₃ ': Light refractive index

100: Backlight module 110: Housing

111: Light exit port 112, 113: Chamber

114: inner side wall 120: light guide plate

121: Light-emitting surface 122: Light-reflecting surface

130: Light splitting layer 131: Microstructure

140: First light source 150: Second light source

160: Gap layer 170: Optical diaphragm group

200: LCD module

330: Light splitting layer 331: Microstructure

430: Light splitting layer 431: Microstructure

460: Gap

910: Color filter 920: LCD module

Detailed ways

Please refer to FIG. 2 and FIG. 3 , FIG. 2 is a schematic cross-sectional view showing a backlight module and a liquid crystal display module according to a first embodiment of the present invention, and FIG. 3 is a schematic diagram showing a backlight module according to a first embodiment of the present invention. Group cutaway diagram. The backlight module 100 of this embodiment is preferably an edge-lit backlight module, which is disposed under a liquid crystal display module 200 to form a liquid crystal display (Liquid Crystal Display; LCD). The backlight module 100 includes a housing 110 , a light guide plate 120 , a light splitting layer 130 , a first light source 140 , a second light source 150 , a gap layer 160 and an optical film set 170 . The casing 110 is used to carry the light guide plate 120 , the light splitting layer 130 , the first light source 140 , the second light source 150 , the gap layer 160 and the optical film set 170 . The light guide plate 120 is used to guide the light from the first light source 140 and the second light source 150 to enter the light-splitting layer 130, and the light-splitting layer 130 is to make the light from the first light source 140 emit light toward the first viewing angle range a, and make the second light source 140 emit light toward the first viewing angle range a. The light from the two light sources 150 emits light toward the second viewing angle range b, wherein the position of the first light source 140 is relative to the first viewing angle range a, and the position of the second light source 150 is relative to the second viewing angle range b. Therefore, the backlight module 100 of this embodiment can emit light toward at least two viewing angle ranges at the same time. The gap layer 160 is formed between the light guide plate 120 and the light-splitting layer 130 , and the optical film set 170 is disposed above the light-splitting layer 130 to perform optical improvement actions for different purposes.

As shown in FIG. 2 , the housing 110 of this embodiment has a light exit 111 and chambers 112 and 113 . The light outlet 111 is used to emit light. In this embodiment, the housing 110 can form a lampshade with an airtight structure to prevent light from leaking from parts other than the light outlet 111. The housing 110 is made of an opaque material Made of, for example: plasticized material, metal material or a combination of the above materials. The cavities 112 and 113 are respectively formed on two sides of the casing 110 for accommodating the first light source 140 and the second light source 150 respectively. The inner sidewalls 114 of the chambers 112 and 113 can be coated with high reflectivity materials, such as gold, silver, aluminum or a combination of the above materials, so that part of the incident light that does not enter the light guide plate 120 can be reflected to the light guide plate Among 120.

As shown in Figure 2, the first light source 140 and the second light source 150 of this embodiment are, for example: cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp; CCFL), hot cathode fluorescent lamp (Hot Cathode Fluorescent Lamp; HCFL), A light-emitting diode (Light-Emitting Diode; LED), an organic light-emitting diode (Organic Light Emitting Diode; OLED) or an electro-luminescent sheet (Electro-Luminescence; EL) is used to emit light into the light guide plate 120 sideways. Wherein, the first light source 140 and the second light source 150 are respectively controlled by independent power sources (not shown).

As shown in FIG. 2 , the light guide plate 120 of this embodiment is accommodated in the housing 110 to guide the light from the first light source 140 and the second light source 150 to enter the light splitting layer 130. The light guide plate 120 is, for example, formed by injection molding. The way to make a flat structure, the material such as acrylic or PMMA. The light guide plate 120 has a light emitting surface 121 and a light reflecting surface 122 . The light emitting surface 121 is located on the front of the light guide plate 120 and corresponds to the light emitting port 111 of the casing 110 , so that light enters the light splitting layer 130 . The light reflection surface 122 is located on the bottom surface of the light guide plate 120 and is opposite to the light exit surface 121 for totally reflecting the side light from the first light source 140 and the second light source 150 to the light exit port 111 . Wherein, the light reflecting surface 122 can achieve the function of reflecting light by disposing a reflective sheet or coating a high reflectivity material (such as a metal material).

Please refer to FIG. 3 and FIG. 4 . FIG. 4 is a perspective view illustrating a partial light splitting layer according to a first embodiment of the present invention. The light-splitting layer 130 of this embodiment is disposed on the light guide plate 120 to make the separated light emit light toward a specific viewing angle range. The light splitting layer 130 is made of materials such as photocurable resin, acrylic or PMMA. Wherein, the light refractive index n ₁ (about 1.5) of the light guide plate 120 is substantially the same as the light refractive index n ₂ of the material of the light-splitting layer 130. Therefore, when light enters the light-splitting layer 130 from the light guide plate 120, the light can be almost There is no broken line phenomenon, that is, the light does not change direction and angle at this time. The light-splitting layer 130 is provided with a plurality of microstructures 131, and these microstructures 131 are a plurality of raised structures, which are protruded between the light-splitting layer 130 and the light guide plate 120, and arranged closely on the light-emitting surface 121 of the light guide plate 120 In general, the shape of the microstructures 131 can be, for example, a cone or a semicircle. Taking the cone-shaped microstructure 131 as an example, the base angle of the cone is about 15 degrees to 75 degrees. The gap layer 160 is formed between the light guide plate 120 and the light splitting layer 130, wherein the light refractive index _n3 of the gap layer 160 is substantially smaller than the light refractive index _n1 of the light guide plate 120 and the light refractive index _n2 of the light splitting layer 130, respectively, In this way, the light entering the gap layer 160 from the light guide plate 120 or the light splitting layer 130 can be totally reflected. The gap layer 160 is, for example, formed by using air as a medium (n ₃ is approximately 1), or is filled with a material having a low refractive index. The optical film set 170 of this embodiment is, for example, a diffusion sheet, a prism sheet, a Brightness Enhancement Film (BEF), a reflective Brightness Enhancement Film (DBEF), a non-multilayer film reflective polarizer Diffused Reflective Polarizer Film (DRPF) or any combination of the above, which is disposed above the light-splitting layer 130 to enable the light emitted by the light-splitting layer 130 to perform optical improvement actions for different purposes.

When the backlight module of this embodiment emits light, the first light source 140 and the second light source 150 emit side light to the light guide plate 120 respectively, and at this time, part of the light can be directly injected into the light-splitting layer 130 by the microstructures 131 Among them, part of the light may enter the microstructures 131 after being reflected by the light reflective surface 122 of the light guide plate 120 , wherein the light incident from the light guide plate 120 to the light splitting layer 130 is incident at different angles. Moreover, at this time, the light incident from the light guide plate 120 to the gap layer 160 is totally reflected and cannot enter the light splitting layer 130 . When the light in the microstructure 131 is incident on the gap layer 160 , the light is totally reflected and deflected in one direction. When the light is emitted from the light splitting layer 130, the light can be refracted and further deflected in this direction.

Therefore, through the microstructures 131 of the light splitting layer 130 and the gap layer 160, the light can be limited to exit only in a predetermined direction and angle range, that is, the light can be limited to exit only within a specific viewing angle range, wherein, when the second light source When 150 is turned off, the first light source 140 emits light toward the first viewing angle range a, and when the first light source 140 is turned off, the second light source 150 emits light toward the second viewing angle range b. Therefore, the backlight module 100 of this embodiment can provide backlights for different viewing angles.

When the backlight module of this embodiment is applied to a liquid crystal display device, the first light source 140 and the second light source 150 of the backlight module 100 can alternately switch on and off according to a predetermined frequency, and synchronously correspond to the liquid crystal display module. The image updating operation in 200 is used to simultaneously display different images toward the first viewing angle range a and the second viewing angle range b. Therefore, the liquid crystal display device used in the backlight module of this embodiment can simultaneously display different images in different viewing angle ranges, thereby achieving the effect of dual viewing angle (DualView) simultaneous display.

Please refer to FIG. 5 , which shows a perspective view of a light splitting layer according to a second embodiment of the present invention. Only the differences between this embodiment and the first embodiment will be described below, and the similarities will not be repeated here. Compared with the first embodiment, each of the microstructures 331 of the light splitting layer 330 in the second embodiment is a strip-shaped prismatic structure, and the two sides of each of the microstructures 331 are respectively opposite to the first light source 140 and the second light source 150, so that the light from the first light source 140 and the second light source 150 can be effectively emitted only toward a predetermined viewing angle range, thereby improving the light extraction efficiency within a single viewing angle range.

Please refer to FIG. 6 , which shows a schematic cross-sectional view of a light guide plate and a light splitting layer according to a third embodiment of the present invention. Only the differences between this embodiment and the first embodiment will be described below, and the similarities will not be repeated here. Compared with the first embodiment, the microstructures 431 of the light-splitting layer 430 of the third embodiment are a plurality of recessed structures, which are recessed between the light-splitting layer 130 and the light guide plate 120, and the recessed shapes of the microstructures 431 can be, for example, Conical or semicircular. At this time, there is no gap layer 160 between the light splitting layer 430 and the light guide plate 120. On the contrary, a gap 460 is formed in the concave shape of each of these microstructures 431, wherein the light refractive index n ₃ ′ of the gap 460 is respectively substantially smaller than The light refractive index n ₁ of the light guide plate 120 and the light refractive index n ₂ of the light-splitting layer 430 are used so that the light entering the gap 460 from the light guide plate 120 or the light-splitting layer 430 can be totally reflected. Therefore, the microstructures 431 of the light-splitting layer 430 and the gap layer 460 can respectively limit light rays to be emitted only within specific viewing angle ranges, so as to provide backlight for different viewing angle ranges.

It can be seen from the above embodiments of the present invention that the backlight module of the present invention can provide backlights for different viewing angles. When the backlight module of the present invention is applied to a liquid crystal display device, the liquid crystal display device can simultaneously display different image images in different viewing angle ranges, so that different images can be viewed from different viewing angle ranges toward a single display device at the same time, reducing Settings for additional display devices.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall prevail as defined by the appended claims.

Claims (11)

1. liquid crystal indicator comprises at least:

One display panels; And

One module backlight is arranged at this below this liquid crystal display module, and wherein this module backlight comprises at least:

One light guide plate;

One beam splitter layer is arranged at this on this light guide plate, and wherein this beam splitter layer is provided with a plurality of microstructures;

One first light source is arranged at one first side of this light guide plate; And

One secondary light source is arranged at one second side of this light guide plate.

2. liquid crystal indicator as claimed in claim 1 wherein also comprises at least:

One clearance layer is formed between this light guide plate and this beam splitter layer.

3. liquid crystal indicator as claimed in claim 2, wherein the optical index of this clearance layer is respectively less than the optical index of this light guide plate and the optical index of this beam splitter layer.

4. liquid crystal indicator as claimed in claim 1, wherein the optical index of this light guide plate is the optical index that is same as this beam splitter layer.

5. liquid crystal indicator as claimed in claim 1, wherein said microstructure are a plurality of bulge-structures.

6. liquid crystal indicator as claimed in claim 1, wherein said microstructure are a plurality of sunk structures.

7. liquid crystal indicator as claimed in claim 1, wherein said microstructure are a plurality of semicircle microstructures.

8. liquid crystal indicator as claimed in claim 1, wherein said microstructure are a plurality of taper microstructures.

9. liquid crystal indicator as claimed in claim 8, the base angle of wherein said taper microstructure are between 75 degree between 15 degree.

10. liquid crystal indicator as claimed in claim 1, wherein said microstructure are a plurality of strip prismatic structure.

11. liquid crystal indicator as claimed in claim 1, wherein this first light source and this secondary light source can be according to a preset frequency hocket respectively on-off action and the frame updating actions of being carried out corresponding to this liquid crystal display module synchronously.

Images