CN101126862A - Side light-entering type backlight assembly - Google Patents

Abstract

The invention discloses a side-edge light-entering type backlight assembly which comprises a first light guide plate, a plurality of second light guide plates, a plurality of red light point light sources, a plurality of green light point light sources and a plurality of blue light point light sources. The first light guide plate is provided with a first light emitting surface, a bottom surface and a first light incident surface connecting the first light emitting surface and the bottom surface. The second light guide plate is arranged beside the first light incident surface. In addition, the red light point light source, the green light point light source and the blue light point light source are respectively arranged beside the second light guide plate. The light rays emitted by the red light point light source, the green light point light source and the blue light point light source are mixed into white light through the second light guide plates and are incident to the first light incident surface. The backlight assembly of the invention adopts the framework of the second light guide plate, and can obtain white light with high color saturation and low color cast.

Description

Side-illuminated backlight assembly

technical field

The present invention relates to a backlight assembly, and in particular to a side-illuminated backlight assembly.

Background technique

Due to the increasing demand for displays, the industry is fully committed to the development of related displays. Among them, the cathode ray tube (Cathode Ray Tube) has been monopolizing the display market for many years due to its excellent display quality and technological maturity. However, due to the rise of the concept of green environmental protection, the characteristics of large energy consumption and large radiation, and the limited space for product flattening, it cannot meet the market demand for light, thin, short, small, beautiful and low power consumption. market trends. Therefore, thin film transistor liquid crystal displays (Thin Film Transistor Liquid Crystal Display, TFT-LCD) with superior characteristics such as high image quality, good space utilization efficiency, low power consumption, and no radiation have gradually become the mainstream of the market.

For TFT-LCD module, it is mainly composed of a liquid crystal display panel and a backlight module. Among them, the liquid crystal display panel is usually composed of a thin film transistor array substrate (thin film transistor array substrate), a color filter substrate (color filter substrate) and a liquid crystal layer arranged between the two substrates, and the backlight assembly is used to provide The surface light source required by the liquid crystal display panel enables the liquid crystal display components to achieve the display effect. In addition, the backlight assembly can be further divided into a side-illuminated backlight assembly and a direct-lit backlight assembly. The following will take the side-illuminated backlight assembly as an example for illustration.

FIG. 1A is a top view of a conventional side-lit backlight assembly, and FIG. 1B is a cross-sectional view of the conventional side-lit backlight assembly of FIG. 1A . Please refer to FIG. 1A and FIG. 1B , the existing side-illuminated backlight assembly includes a backplane 130, a flexible printed circuit (Flexible Printed Circuit, FPC) 150, several white light emitting diodes (Light Emitting Diode, LED) 120, Light Guide Plate (LGP) 110 , reflector 160 , several layers of optical film 170 and plastic frame 140 . Wherein, the light guide plate 110 is disposed inside the back plate 130 , and the reflection sheet 160 is disposed between the light guide plate 110 and the back plate 130 . The white light emitting diode 120 is disposed on the flexible circuit board 150 and is located beside the light guide plate 110 . In addition, the plastic frame 140 is disposed on the back plate 130 , and the optical film 170 is disposed between the plastic frame 140 and the light guide plate 110 .

More specifically, the white light emitting diode 120 is a point light source, and the light emitted by the white light emitting diode 120 becomes a surface light source after passing through the light guide plate 110 . A liquid crystal display adopting such an existing side-illuminated backlight assembly may have problems such as insufficient color saturation.

In response to the above phenomenon, it was later proposed to change the white light emitting diodes 120 in the side-illuminated backlight assembly into a group of three red light emitting diodes, blue light emitting diodes and green light emitting diodes.

FIG. 1C is an exploded view of the above-mentioned conventional backlight assembly of a side-illuminated liquid crystal display. Please refer to Figure 1C, the structure of this side-illuminated backlight module is roughly the same as the backlight assembly in Figure 1A and Figure 1B, but the biggest difference is that this side-illuminated backlight assembly uses green light-emitting diodes 120g, red The light emitting diode 120r and the blue light emitting diode 120b are used to mix white light.

However, since the light emitted by the green LED 120g, the red LED 120r and the blue LED 120b cannot be completely and uniformly mixed in the light guide plate, the liquid crystal display using this side-illuminated backlight assembly will produce The case of local color cast.

Contents of the invention

The purpose of the present invention is to provide a side-illuminated backlight assembly to improve color saturation.

To achieve the above or other objectives, the present invention proposes a side-illuminated backlight assembly, which includes a first light guide plate, multiple second light guide plates, multiple red point light sources, multiple green point light sources and multiple a blue light source. Wherein the first light guide plate has a first light emitting surface, a bottom surface and a first light incident surface connecting the first light emitting surface and the bottom surface. A plurality of second light guide plates are arranged beside the first light incident surface. A plurality of red light, blue light and green light point light sources are respectively arranged beside the second light guide plate. The light emitted by the red point light source, the green light point light source and the blue light point light source are mixed into white light through the second light guide plates and incident on the first light incident surface.

In an embodiment of the present invention, each second light guide plate has a second light incident surface and a second light exit surface respectively, and two opposite sides of the second light incident surface are respectively connected with two opposite sides of the second light exit surface. The second light emitting surface is located beside the first light incident surface, and the red point light source, the green light point light source and the blue light point light source are located beside the second light incident surface.

In an embodiment of the present invention, the second light incident surface is a curved surface, and the second light exit surface is a plane.

In an embodiment of the present invention, the second light incident surface is a plane, and the second light exit surface is a curved surface.

In one embodiment of the present invention, each second light guide plate has a second light-incident surface, a second light-exit surface, and two side surfaces, and the sides are respectively connected between the second light-incidence surface and the second light-exit surface, and the second light-exit surface is located on the second light-exit surface. Next to the first light incident surface, and the red point light source, the green light point light source and the blue light point light source are located next to the second light incident surface.

In an embodiment of the present invention, the second light incident surface and the second light exit surface are planes.

In an embodiment of the present invention, the included angle between the second light-emitting surface and the side surface is between 120 degrees and 150 degrees.

In one embodiment of the present invention, each second light guide plate has a first sub-light incident surface, a second sub-light incident surface, a third sub-light incident surface, and a second light-emitting surface, and the first sub-light incident surface and the second light-emitting surface The faces are opposite, the first sub-light incident surface is connected between the second sub-light incident surface and the third sub-light incident surface, the second light-emitting surface is located next to the first light-entrance surface, and the red light point light source, the green light point light source and the blue light The point light sources are respectively located beside the first sub-light incident surface, the second sub-light incident surface and the third sub-light incident surface.

In an embodiment of the present invention, the first sub-light incident surface, the second sub-light incident surface, the third sub-light incident surface and the second light-emitting surface are planes.

In an embodiment of the present invention, the included angle between the first sub-light incident surface and the second sub-light incident surface is between 120 degrees and 150 degrees.

In an embodiment of the present invention, the included angle between the first sub-light incident surface and the third sub-light incident surface is between 120 degrees and 150 degrees.

In an embodiment of the present invention, each second light guide plate further has two side surfaces, respectively connecting between the second sub-light-incident surface and the second light-exit surface and between the third sub-light-incident surface and the second light-exit surface.

In an embodiment of the present invention, the first sub-light incident surface, the second sub-light incident surface, the third sub-light incident surface and the second light-emitting surface are planes, and the side surfaces are curved surfaces.

In an embodiment of the present invention, the first sub-light incident surface and the second light-emitting surface are flat surfaces, and the second sub-light-incident surface and the third sub-light-incident surface are curved surfaces.

In an embodiment of the present invention, the side-illuminated backlight assembly further includes a backplane, and the first light guide plate is disposed in the backplane.

In an embodiment of the present invention, the side-illuminated backlight assembly further includes a plastic frame disposed on the back plate and located above the first light guide plate.

In an embodiment of the present invention, the side-illuminated backlight assembly further includes a flexible circuit board, and the red point light source, the green light point light source, the blue light point light source and the second light guide plate are disposed on the flexible circuit board.

In an embodiment of the present invention, the side-illuminated backlight assembly further includes a reflection sheet disposed on the bottom surface of the first light guide plate.

In an embodiment of the present invention, the side-illuminated backlight assembly further includes at least one layer of optical film disposed on the first light-emitting surface of the first light guide plate.

In an embodiment of the present invention, the first light guide plate and the second light guide plate are integrally formed.

The present invention uses a plurality of second light guide plates to mix red, blue and green light to form white light. Therefore, compared with the prior art, the side-illuminated backlight assembly of the present invention has better color saturation.

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

Description of drawings

FIG. 1A is a top view of a conventional side-illuminated backlight assembly.

FIG. 1B is a cross-sectional view of the conventional side-lit backlight assembly shown in FIG. 1A .

FIG. 1C is an exploded view of a conventional backlight assembly of a side-illuminated liquid crystal display.

FIG. 2A is an exploded view of a side-lit backlight assembly according to the first embodiment of the present invention.

FIG. 2B is a top view of the second light guide plate of FIG. 2A .

FIG. 3 is a top view of a second light guide plate according to the second embodiment of the present invention.

FIG. 4 is a top view of a second light guide plate according to a third embodiment of the present invention.

FIG. 5 is a top view of a second light guide plate according to a fourth embodiment of the present invention.

FIG. 6 is a top view of a second light guide plate according to a fifth embodiment of the present invention.

FIG. 7 is a top view of a second light guide plate according to a sixth embodiment of the present invention.

Detailed ways

first embodiment

FIG. 2A is an exploded view of the side-lit backlight assembly of the first embodiment of the present invention, and FIG. 2B is a top view of the second light guide plate of FIG. 2A . Please refer to FIG. 2A and FIG. 2B , the side-lit backlight assembly of this embodiment includes a first light guide plate 200, a plurality of second light guide plates 210, a plurality of red point light sources 220r, a plurality of blue light point sources 220b and a plurality of A green point light source 220g. Wherein, the first light guide plate has a first light emitting surface 201 , a bottom surface 202 and a first light incident surface 203 connecting the first light emitting surface 201 and the bottom surface 202 . In addition, the second light guide plate 210 is disposed beside the first light incident surface 202 . The red point light sources 220r , the blue point light sources 220b and the green point light sources 220g are respectively arranged beside the second light guide plate 210 . Therefore, the light emitted by the red point light source 220 r , the blue light point light source 220 b and the green light point light source 220 g is mixed into white light through the second light guide plates 210 and enters the first light incident surface 203 .

In more detail, in this embodiment, the second light guide plate 210 has a second light-emitting surface 211 , a first sub-light-incident surface 212 , a second sub-light-incident surface 213 , a third sub-light-incident surface 214 and two side surfaces 215 with 216. Wherein, the first sub-light incident surface 212 is opposite to the second light-emitting surface 211 , and the first sub-light-incident surface 212 connects the second sub-light-incident surface 213 and the third sub-light-incident surface 214 . The two side surfaces 215 and 216 are respectively connected to the second light-emitting surface 211 and the second sub-light-incident surface 213 as well as the second light-emitting surface 211 and the third sub-light-incident surface 214 . In this embodiment, except that the two side surfaces 215 and 216 are curved surfaces, all other sides are flat surfaces. However, the two side surfaces 215 and 216 of this embodiment may also be planes.

In addition, the red point light source 220r, the green point light source 220g, and the blue point light source 220b are placed beside the first light-incident sub-surface 212, the second light-incident sub-surface 213, and the third light-incident sub-surface 214 respectively. However, the present invention does not limit the arrangement of the red point light sources 220r, the green point light sources 220g, and the blue point light sources 220b, which will be described in detail later.

Please continue to refer to FIG. 2B , there is an included angle θ1 between the first sub-light incident surface 212 and the second sub-light incident surface 213 , and an included angle θ2 between the first sub-light incident surface 212 and the third sub-light incident surface 214 . The aforementioned included angle θ1 and included angle θ2 may be the same or different. In addition, the angle θ1 may be between 120 degrees and 150 degrees, and the angle θ2 may be between 120 degrees and 150 degrees.

In addition, the material of the second light guide plate 210 may be polymethylmethacrylate (PMMA), polycarbonate (polycarbonate, PC) or other transparent materials. In addition, the forming method of the second light guide plate 210 can be cutting forming or injection forming. Furthermore, as far as this embodiment is concerned, other surfaces except the first sub-light incident surface 212, the second sub-light incident surface 213, the third sub-light incident surface 214 and the second light-emitting surface 211 can be formed with Layers of highly reflective material to improve light mixing. In addition, the red point light source 220r, the green point light source 220g and the blue point light source 220b may be light emitting diodes (LEDs) or organic light emitting diodes (Organic Light Emitting Diode, OLED).

Please continue to refer to FIG. 2A , the backlight assembly of this embodiment further includes a backplane 230 , a plastic frame 240 , a flexible circuit board 250 , a reflection sheet 260 and at least one optical film 270 . Wherein, the first light guide plate 200 is disposed in the back plate 230 . In addition, the red point light source 220r , the green point light source 220g and the blue point light source 220b are disposed on the flexible circuit board 250 , and the second light guide plate 210 is on the flexible circuit board 250 . The reflection sheet 260 is disposed on the bottom surface 202 of the first light guide plate 200 , and the optical film 270 is disposed on the first light emitting surface 201 of the first light guide plate 200 . In addition, the plastic frame 240 is disposed on the back plate 230 and located above the first light guide plate 200 . It should be noted that the first light guide plate 200 and the second light guide plate 210 in this embodiment are formed separately, but the first light guide plate 200 and the second light guide plate 210 may also be integrally formed.

Since the present invention utilizes the second light guide plate to mix red light, blue light and green light to form white light with high saturation, compared with the prior art, the liquid crystal display with such a side-illuminated backlight assembly has better performance. Color saturation.

second embodiment

The structure of the backlight assembly of the second embodiment is substantially the same as that of the first embodiment, but the main difference lies in the change of the structure of the second light guide plate 310 .

FIG. 3 is a top view of a second light guide plate according to the second embodiment of the present invention. Referring to FIG. 3 , the second light guide plate 310 has a second light-emitting surface 311 , a first sub-light-incident surface 312 , a second sub-light-incident surface 313 , a third sub-light-incident surface 314 , and two side surfaces 315 and 316 . Wherein, the first sub-light incident surface 312 is opposite to the second light-emitting surface 311 , and the first sub-light-incident surface 312 connects the second sub-light-incident surface 313 and the third sub-light-incident surface 314 . The side surface 315 is connected between the second light-emitting surface 311 and the second sub-light-incident surface 313 , and the side surface 316 is connected between the second light-emitting surface 311 and the third sub-light-incident surface 314 . In addition, the red point light source 320r, the green point light source 320g, and the blue point light source 320b correspond to the first sub-light incident surface 312, the second sub-light incident surface 313, and the third sub-light incident surface 314, respectively.

In this embodiment, the second sub-light incident surface 313 and the third sub-light incident surface 314 are curved surfaces, while the first sub-light incident surface 312 and the second light-emitting surface 311 are flat surfaces. In addition, the two side surfaces 315 and 316 are flat surfaces, but in other embodiments, the two side surfaces 315 and 316 can also be curved surfaces.

third embodiment

The structure of the backlight assembly of the third embodiment is substantially the same as that of the first embodiment, but the main difference lies in the structure of the second light guide plate 410 .

FIG. 4 is a top view of a second light guide plate according to a third embodiment of the present invention. Please refer to FIG. 4 , the second light guide plate 410 of this embodiment has a second light emitting surface 411 and a second light incident surface 412 . Wherein the second light incident surface 412 is a curved surface, while the second light exit surface 411 may be a plane. However, the second light-emitting surface 411 may also be a convex curved surface or a concave curved surface with a curvature different from that of the second light-incident surface 412 . In addition, the red point light source 420 r , the green light point light source 420 g and the blue light point light source 420 b are located beside the second light incident surface 412 .

In more detail, the curvature of the second light incident surface 412 can be designed so that when the light emitted by the red point light source 420r, the green light point light source 420g and the blue light point light source 420b passes through the second light guide plate 410, it can be focused on the second light output surface. 411 on the focus point F.

Fourth embodiment

The structure of the backlight assembly of the fourth embodiment is substantially the same as that of the first embodiment, but the main difference lies in the structure of the second light guide plate 510 .

FIG. 5 is a top view of a second light guide plate according to a fourth embodiment of the present invention. Please refer to FIG. 5 , the second light guide plate 510 of this embodiment has a second light emitting surface 511 and a second light incident surface 512 . Wherein the second light emitting surface 511 is a curved surface, while the second light incident surface 512 may be a plane. However, the second light incident surface 512 can also be a convex curved surface or a concave curved surface with a curvature different from that of the second light outgoing surface 511 . In addition, the red point light source 520r , the green point light source 520g and the blue point light source 520b are located beside the second light incident surface 512 .

fifth embodiment

The structure of the backlight assembly of the fifth embodiment is substantially the same as that of the first embodiment, but the main difference lies in the structure of the second light guide plate 610 .

FIG. 6 is a top view of a second light guide plate according to a fifth embodiment of the present invention. Referring to FIG. 6 , the second light guide plate 610 has a second light emitting surface 611 , a second light incident surface 612 , and two side surfaces 613 and 614 . In this embodiment, the second light emitting surface 611 , the second light incident surface 612 , the two side surfaces 613 and 614 are planes. However, the second light emitting surface 611 , the second light incident surface 612 , the two side surfaces 613 and 614 may also be curved surfaces. In addition, the red point light source 620 r , the blue light point light source 620 b and the green light point light source 620 g are located beside the second light incident surface 612 .

In addition, the included angle between the second light-emitting surface 611 and the side surface 613 is θ3, and the included angle between the second light-emitting surface 611 and the side surface 614 is θ4. In addition, the above-mentioned included angle θ3 and included angle θ4 may be the same or different. In addition, the angle θ3 may be between 120 degrees and 150 degrees, and the angle θ4 may be between 120 degrees and 150 degrees.

Sixth embodiment

The structure of the backlight assembly of the sixth embodiment is substantially the same as that of the first embodiment, but the main difference lies in the structure of the second light guide plate 710 .

FIG. 7 is a top view of a second light guide plate according to a sixth embodiment of the present invention. Please refer to FIG. 7 , the second light guide plate 710 includes a second light-emitting surface 711 , a first sub-light-incident surface 712 , a second sub-light-incident surface 713 and a third sub-light-incident surface 714 . In this embodiment, the second light-emitting surface 711 , the first sub-light-incident surface 712 , the second sub-light-incident surface 713 and the third sub-light-incident surface 714 are planes. However, the second light-emitting surface 711 , the first sub-light-incident surface 712 , the second sub-light-incident surface 713 or the third sub-light-incident surface 714 may also be curved surfaces. In addition, the red point light source 720r is located next to the first sub-light incident surface 712 , the green light point light source 720g is located next to the second sub-light incident surface 713 , and the blue light point light source 720b is located next to the third sub-light incident surface 714 .

In addition, there is an included angle θ5 between the first sub-light incident surface 712 and the second sub-light incident surface 713 , and an included angle θ6 between the first sub-light incident surface 712 and the third sub-light incident surface 714 . The included angle θ5 and the included angle θ6 may be the same or different. In addition, the angle θ5 may be between 120 degrees and 150 degrees, and the angle θ6 may be between 120 degrees and 150 degrees.

To sum up, the present invention uses a plurality of second light guide plates together with red point light sources, blue light point light sources and green light point light sources, so as to mix white light. Therefore, compared with the prior art, the side-illuminated backlight assembly of the present invention has better color saturation and improves the occurrence of color shift. In addition, the present invention also proposes several second light guide plates with different configurations, all of which can achieve the above-mentioned purpose of uniformly mixing white light.

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

Claims (20)

1. A side-illuminated backlight assembly, comprising: A first light guide plate, having a first light-emitting surface, a bottom surface, and a first light-incident surface connecting the first light-emitting surface and the bottom surface; a plurality of second light guide plates arranged beside the first light incident surface; A plurality of red light point light sources are respectively arranged beside the second light guide plates; A plurality of green light point light sources are respectively arranged beside the second light guide plates; and A plurality of blue point light sources are respectively arranged beside the second light guide plates, wherein the light emitted by the red light point sources, the green light point sources and the blue light sources are mixed through the second light guide plates The white light is incident on the first light incident surface. 2. The side-illuminated backlight assembly according to claim 1, wherein each of the second light guide plates has a second light incident surface and a second light exit surface, and the two sides of the second light incident surface The opposite sides are respectively connected with two opposite sides of the second light-emitting surface, the second light-emitting surface is located beside the first light-incident surface, and the red point light sources, the green light point light sources and the blue light points The light source is located beside the second light incident surface. 3. The side-lit backlight assembly as claimed in claim 2, wherein the second light-incident surface is a curved surface, and the second light-emitting surface is a plane. 4. The side-lit backlight assembly as claimed in claim 2, wherein the second light-incident surface is a plane, and the second light-emitting surface is a curved surface. 5. The side-illuminated backlight assembly according to claim 1, wherein each of the second light guide plates has a second light-incident surface, a second light-exit surface and two side surfaces, and the side surfaces are respectively connected to the Between the second light incident surface and the second light exit surface, the second light exit surface is located beside the first light incident surface, and the red point light sources, the green light point light sources and the blue light point light sources are located on the Next to the second light incident surface. 6. The side-lit backlight assembly as claimed in claim 5, wherein the second light-incident surface and the second light-emitting surface are planes. 7. The side-illuminated backlight assembly as claimed in claim 6, wherein an angle between the second light-emitting surface and the side surface is between 120 degrees and 150 degrees. 8. The side-illuminated backlight assembly according to claim 1, wherein each of the second light guide plates has a first sub-light incident surface, a second sub-light incident surface, and a third sub-light incident surface. surface and a second light-emitting surface, the first sub-light-incident surface is opposite to the second light-emitting surface, the first sub-light-incident surface is connected between the second sub-light-incident surface and the third sub-light-incidence surface, the The second light emitting surface is located beside the first light incident surface, and the red point light sources, the green light point light sources and the blue light point light sources are respectively located on the first sub light incident surface and the second sub light incident surface And the third son next to the light incident surface. 9. The side-lit backlight assembly according to claim 8, wherein the first sub-light incident surface, the second sub-light incident surface, the third sub-light incident surface and the second light-emitting surface for the plane. 10. The side-illuminated backlight assembly of claim 8, wherein an angle between the first sub-light incident surface and the second sub-light incident surface is between 120 degrees and 150 degrees. 11. The side-lit backlight assembly of claim 8, wherein an included angle between the first sub-light incident surface and the third sub-light incident surface is between 120 degrees and 150 degrees. 12. The side-illuminated backlight assembly according to claim 8, wherein each of the second light guide plates further has two side surfaces, which are respectively connected between the second sub-light-incident surface and the second light-exit surface and Between the third sub-light incident surface and the second light exit surface. 13. The side-lit backlight assembly according to claim 12, wherein the first sub-light incident surface, the second sub-light incident surface, the third sub-light incident surface and the second light-emitting surface is a plane, and the sides are curved. 14. The side-illuminated backlight assembly according to claim 12, wherein the first sub-light incident surface and the second light-emitting surface are planes, and the second sub-light incident surface and the third sub-light surface The incident surface is a curved surface. 15. The side-illuminated backlight assembly according to claim 1, further comprising a backplane, the first light guide plate is disposed in the backplane. 16. The side-illuminated backlight assembly according to claim 15, further comprising a plastic frame disposed on the back panel and located above the first light guide plate. 17. The side-illuminated backlight assembly according to claim 1, further comprising a flexible circuit board, and the red point light sources, the green point light sources, the blue point light sources and the The second light guide plates are configured on the flexible circuit board. 18. The side-illuminated backlight assembly of claim 1, further comprising a reflective sheet disposed on the bottom surface of the first light guide plate. 19. The side-lit backlight assembly of claim 1, further comprising at least one optical film disposed on the first light-emitting surface of the first light guide plate. 20. The side-lit backlight assembly as claimed in claim 1, wherein the first light guide plate and the second light guide plates are integrally formed.

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