CN101393354A - Backlight module and liquid crystal display using the same - Google Patents

Abstract

A backlight module includes a light guide plate, a light source, and a light-transmitting elastic body. The light guide plate has a first light-emitting surface, a bottom surface relative to the first light-emitting surface, and at least one light-incident surface contacting the first light-emitting surface and the bottom surface. The light source is arranged beside the light-incident surface, and includes a circuit board and a plurality of light-emitting diode devices. Each light-emitting diode device is suitable for emitting light passing through the light-incident surface, and these light-emitting diode devices are electrically connected to the circuit board. The light-transmitting elastic body is arranged between the light-incident surface and each light-emitting diode device.

Description

Backlight module and liquid crystal display using the backlight module

technical field

The invention relates to a backlight module, and in particular to a liquid crystal display using the backlight module.

Background technique

FIG. 1 is a schematic top view of a conventional backlight module, and FIG. 2 is a partially enlarged cross-sectional schematic diagram of the backlight module of FIG. 1 along line I-I. As shown in FIGS. 1 and 2 , the backlight module 100 includes a light guide plate 110 and a light source 120 disposed beside the light incident surface 112 of the light guide plate 110 . The light source 120 includes a circuit board 122 and a plurality of LED packaging structures 124 assembled on the circuit board 122 by surface mount technology (SMT). Each LED packaging structure 124 has a light emitting surface 124 a facing the light incident surface 112 .

It should be noted that when the LED packaging structures 124 are assembled to the circuit board 122 , the light emitting surfaces 124 a will not be on the same plane due to the manufacturing tolerance of surface mount technology. For example, some of the light emitting surfaces 124 a are not parallel to the light incident surface 112 . Alternatively, although the light emitting surfaces 124 a are all parallel to the light incident surface 112 , the light emitting surfaces 124 a maintain different distances from the light incident surface 112 respectively. Therefore, when the light source 120 is assembled to the light incident surface 112 of the light guide plate 110, the light guide plate 110 may press some of these LED packaging structures 124, causing the positions of some of these LED packaging structures 124 to be shifted or damaged, thereby improving Cost of production.

In order to improve the above problems, in the prior art, the manufacturing tolerance is usually reduced by improving the precision of the surface mount technology, or by increasing the distance between the light incident surface 112 of the light guide plate 110 and these LED packaging structures 124, so as to avoid these LEDs. The encapsulation structure 124 is damaged. However, increasing the precision of the surface mount technology will increase the production cost, and increasing the distance between the light incident surface 112 of the light guide plate 110 and the LED packaging structures 124 will reduce the light use efficiency. Therefore, how to improve the light usage efficiency of the backlight module and reduce the production cost will be a subject worthy of efforts.

Contents of the invention

The invention provides a backlight module and a liquid crystal display using the backlight module to reduce production costs and improve light use efficiency.

An embodiment of the invention provides a backlight module, including a light guide plate, a light source, and a light-transmitting elastic body. The light guide plate has a first light exit surface, a bottom surface opposite to the first light exit surface, and at least one light incident surface contacting the first light exit surface and the bottom surface. The light source is arranged beside the light incident surface, and includes a circuit board and a plurality of LED devices. Each light emitting diode device is adapted to emit light through the light incident surface, and these light emitting diode devices are electrically connected to the circuit board. The light-transmitting elastic body is disposed between the light-incident surface and each light-emitting diode device.

Another embodiment of the present invention also provides a liquid crystal display, including a liquid crystal display panel and at least one of the above-mentioned backlight modules. The backlight module is arranged on one side of the liquid crystal display panel to provide the surface light source required by the liquid crystal display panel, and the first light emitting surface of the light guide plate of the backlight module faces the liquid crystal display panel.

Because there is a light-transmitting elastic body between the light guide plate and the light-emitting diode device, the production cost of the backlight module and the liquid crystal display using it can be effectively reduced, and the light use efficiency can be improved.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, preferred embodiments will be described below in detail with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a schematic top view of a conventional backlight module;

FIG. 2 is a partially enlarged schematic cross-sectional view of the backlight module of FIG. 1 along the line I-I;

3 is a schematic top view of a liquid crystal display according to an embodiment of the present invention;

Fig. 4 is the sectional schematic diagram along I-I line of liquid crystal display of Fig. 3;

5 and 6 are schematic top views of liquid crystal displays according to other embodiments of the present invention.

Detailed ways

The following descriptions of various embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention can be practiced. The direction terms mentioned in the present invention, such as "up", "down", "front", "rear", "left", "right", etc., are only referring to the directions of the drawings. Accordingly, the directional terms are used to illustrate, not to limit, the invention.

FIG. 3 is a schematic top view of a liquid crystal display according to an embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view of the liquid crystal display of FIG. 3 along line I-I. As shown in FIGS. 3 and 4 , the liquid crystal display 200 includes a liquid crystal display panel 300 and at least one backlight module 400 . The backlight module 400 is, for example, a side type BLM, which is disposed on one side of the liquid crystal display panel 300 and includes a light guide plate 410, a light source 420, and a light-transmitting elastic body 430a. In this embodiment, the light guide plate 410 is, for example, a wedge-shaped light guide plate, but the present invention is not limited thereto, and the light guide plate 410 may also be a flat light guide plate. The light guide plate 410 has a light emitting surface 412 facing the liquid crystal display panel 300 , a bottom surface 414 opposite to the light emitting surface 412 , and at least one light incident surface 416 contacting the light emitting surface 412 and the bottom surface 414 .

The light source 420 is disposed beside the light incident surface 416 and includes a circuit board 422 and a plurality of LED devices 424 , and each LED device 424 is adapted to emit light passing through the light incident surface 416 . In this embodiment, each LED device 424 is, for example, a LED packaging structure, and has a light emitting surface 424 a facing the light incident surface 416 . These LED devices 424 are assembled on the circuit board 422 by surface mount technology, for example, to be electrically connected with the circuit board 422 . However, in other embodiments, the LED device 424 can be a LED chip, depending on the designer's requirements.

The light-transmitting elastic body 430a is disposed between the light-incident surface 416 and each light-emitting surface 424a, and its material includes silicone rubber, polyurethane, polyolefin or other light-transmitting and elastic materials. The light provided by the LED devices 424 exits from the light exit surface 424 a and enters the light guide plate 410 through the light-transmitting elastic body 430 a and the light incident surface 416 . Then, the light is emitted through the light emitting surface 412 to form the surface light source required by the liquid crystal display panel 300 .

When the LED devices 424 are assembled on the circuit board 422 by, for example, surface mount technology, the light emitting surfaces 424 a may not be on the same plane due to manufacturing tolerances of the surface mount technology (as shown in FIG. 3 ). Since the transparent elastic body 430a is an elastic material, when the light source 420 is assembled to the light incident surface 416 of the light guide plate 410 , the transparent elastic body 430a can serve as a buffer between the light guide plate 410 and each LED device 424 . In other words, the light-transmitting elastic body 430 a can reduce the pressure exerted by the light guide plate 410 on the LED devices 424 by generating elastic deformation, thereby preventing the LED devices 424 from being displaced or damaged. In addition, since the material of the light-transmitting elastic body 430a is light-transmitting, the light usage efficiency of the backlight module 400 can be improved.

All in all, since these light emitting diode devices 424 can be assembled to the circuit board 422 with low precision, these light emitting diode devices 424 can be buffered by the light-transmitting elastic body 430a and are not easy to produce positional deviation or damage, and the light-transmitting elastic body 430a The material is transparent, so the production cost of the backlight module 400 of this embodiment can be effectively reduced and the light utilization efficiency can be improved.

In this embodiment, the light-transmitting elastic body 430a can cover the light incident surface 416 and the light emitting surfaces 424a of the light guide plate 410 . Therefore, the light usage efficiency of the backlight module 400 can be effectively improved. In addition, if the optical property (eg, refractive index) of the light-transmitting elastic body 430 a is similar to that of the light guide plate 410 , the light usage efficiency of the backlight module 400 can be effectively improved.

In this embodiment, the backlight module 400 further includes a plurality of light scattering particles 440 dispersed in the transparent elastic body 430a. The refractive index of these light-scattering particles 440 is, for example, different from that of the light-transmitting elastomer 430a, so that the light provided by the light-emitting diode devices 424 will be scattered by the light-scattering particles 440 after entering the light-transmitting elastomer 430a to generate The desired scattering effect. In another embodiment, the backlight module 400 further includes a plurality of phosphors (not shown) dispersed in the transparent elastic body 430a, or the transparent elastic body 430a can be a colored transparent elastic body, so that these LEDs The light provided by the device 424 changes color after passing through the light-transmitting elastomer 430 . For example, the light provided by the LED device 424 is blue light, and the blue light passes through the light-transmitting elastic body 430 a with yellow-green phosphor to form white light and enters the light guide plate 410 through the light incident surface 416 .

As shown in FIG. 4 , the backlight module 400 further includes a reflection sheet 450 and an optical film set 460 . The reflection sheet 450 is disposed on the bottom surface 414 and can be used to reflect the light entering the light guide plate 410 to the light exit surface 412 . The optical film set 460 is disposed on the light emitting surface 412 and located between the liquid crystal display panel 300 and the light guide plate 410 . The optical film set 460 is, for example, composed of at least one of a diffuser plate, a prism film, or a brightness enhancement film, which can be used to uniformize the surface light source emitted from the light exit surface 412 and to increase the brightness of the surface light source.

In this embodiment, the light-transmitting elastic body 430 a in FIG. 3 is substantially in the shape of a rectangular column, but the above illustration is not intended to limit the present invention. On the premise of not excessively affecting the light use efficiency, the designer can moderately save the material of the light-transmitting elastic body 430a. 5 and 6 are schematic top views of liquid crystal displays according to other embodiments of the present invention. As shown in FIG. 5 and FIG. 6 , for example, the designer can design the transparent elastic body 430 b into the shape shown in FIG. 5 . Alternatively, the light-transmitting elastic body 430c in FIG. 6 can be designed to have a plurality of separate light-transmitting elastic parts T, and the light provided by these light-emitting diode devices 424 is transmitted to the light guide plate 410 through the corresponding light-transmitting elastic parts T respectively. middle.

To sum up, the backlight module and the liquid crystal display using it have at least the following advantages:

1. Because these light emitting diode devices can be assembled to the circuit board with relatively low precision, these light emitting diode devices can be cushioned by the light-transmitting elastic body so as not to be easily shifted or damaged, and the material of the light-transmitting elastic body is light-transmitting , so the production cost of the backlight module can be effectively reduced and the light utilization efficiency thereof can be improved.

2. The light-transmitting elastic body can cover the light-incident surface of the light guide plate and the light-exit surfaces of each LED device. Therefore, the light usage efficiency of the backlight module can be effectively improved.

3. Since the optical property of the light-transmitting elastomer can be similar to that of the light guide plate, the light usage efficiency of the backlight module can be effectively improved.

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 shall prevail as defined by the appended claims. In addition, any embodiment or claim of the present invention need not achieve all the objects or advantages or features disclosed in the present invention. In addition, the abstract and the title are only used to assist in the search of patent documents, and are not used to limit the scope of rights of the present invention.

Claims (20)

1, a kind of backlight module comprises:

Light guide plate has the light entrance face of bottom surface and described first light-emitting face of at least one contact and the described bottom surface of first light-emitting face, described relatively first light-emitting face;

Light source is disposed at by the described light entrance face, and described light source comprises:

Circuit board; And

A plurality of light-emitting diode assemblies, wherein each described light-emitting diode assembly is suitable for sending the light that passes described light entrance face, and more described light-emitting diode assembly is electrically connected to described circuit board; And

Light transmission elastic body is disposed between described light entrance face and each the described light-emitting diode assembly.

2, backlight module as claimed in claim 1, the material of wherein said light transmission elastic body comprises silicon rubber, polyurethane or polyolefin.

3, backlight module as claimed in claim 1 also comprises a plurality of light diffusing particles, and it intersperses among in the described light transmission elastic body, and wherein the refractive index of each described light diffusing particles is different with the refractive index of described light transmission elastic body.

4, backlight module as claimed in claim 1 also comprises a plurality of fluorescent powder, and it intersperses among in the described light transmission elastic body.

5, backlight module as claimed in claim 1, wherein said light transmission elastic body are coloured light transmission elastic body.

6, backlight module as claimed in claim 1, wherein said light transmission elastic body covers described light entrance face.

7, backlight module as claimed in claim 1, wherein each described light-emitting diode assembly is a package structure for LED.

8, backlight module as claimed in claim 7, wherein each described package structure for LED has second light-emitting face towards described light entrance face, and described light transmission elastic body covers described light entrance face and each described second light-emitting face.

9, backlight module as claimed in claim 1, wherein each described light-emitting diode assembly is a light-emitting diode chip for backlight unit.

10, backlight module as claimed in claim 1 also comprises the reflector plate that is disposed on the described bottom surface.

11, a kind of LCD comprises:

Display panels; And

At least one backlight module is disposed at a side of described display panels, and in order to provide described display panels required area source, wherein said backlight module comprises:

Light guide plate has the light entrance face towards bottom surface and described first light-emitting face of at least one contact and the described bottom surface of first light-emitting face of described display panels, described relatively first light-emitting face;

Light source is disposed at by the described light entrance face, and described light source comprises:

Circuit board; And

A plurality of light-emitting diode assemblies, wherein each described light-emitting diode assembly is suitable for sending the light that passes described light entrance face, and described light-emitting diode assembly is electrically connected to described circuit board; And

At least one light transmission elastic body is disposed between described light entrance face and each the described light-emitting diode assembly.

12, LCD as claimed in claim 11, the material of wherein said light transmission elastic body comprises silicon rubber, polyurethane or polyolefin.

13, LCD as claimed in claim 11, wherein said backlight module also comprises a plurality of light diffusing particles, it intersperses among in the described light transmission elastic body, and the refractive index of each described light diffusing particles is different with the refractive index of described light transmission elastic body.

14, LCD as claimed in claim 11, wherein said backlight module also comprises a plurality of fluorescent powder, it intersperses among in the described light transmission elastic body.

15, LCD as claimed in claim 11, wherein said light transmission elastic body are coloured light transmission elastic body.

16, LCD as claimed in claim 11, wherein said light transmission elastic body covers described light entrance face.

17, LCD as claimed in claim 11, wherein each described light-emitting diode assembly is a package structure for LED.

18, LCD as claimed in claim 17, wherein each described package structure for LED has second light-emitting face towards described light entrance face, and described light transmission elastic body covers described light entrance face and each described second light-emitting face.

19, LCD as claimed in claim 11, wherein each described light-emitting diode assembly is a light-emitting diode chip for backlight unit.

20, LCD as claimed in claim 11, wherein said backlight module also comprises the reflector plate that is disposed on the described bottom surface.

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