CN101303479A - Backlight Module and LCD Display - Google Patents

Abstract

The invention discloses a backlight module which is suitable for a liquid crystal display and comprises a supporting frame and a light emitting diode module. The support frame is provided with at least one through hole. The light emitting diode module comprises at least one circuit board and a plurality of light emitting diodes. The circuit board of the light emitting diode module is provided with a bearing surface. The light emitting diodes of the light emitting diode module are arranged on the bearing surface of the circuit board and are electrically connected with the circuit board, wherein the light emitting diodes penetrate through the through holes and are positioned in the supporting frame, and the circuit board is fixed outside the supporting frame by the bearing surface facing the supporting frame. Because the circuit board is exposed outside the support frame, the heat energy generated by the light emitting diode can be quickly transferred to the outside of the backlight module, so that the backlight module has good heat dissipation efficiency.

Description

Backlight Module and LCD Display

technical field

The present invention relates to a light source module and a display, and in particular to a backlight module (backlight module) and a liquid crystal display (Liquid Crystal Display device, LCD device).

Background technique

With the progress of science and technology, displays are gradually widely used by the public. To meet people's needs, displays have changed from larger and heavier cathode ray tubes (Cathode Ray Tube, CRT) to thinner and lighter liquid crystal displays (Liquid Crystal Display, LCD) as the mainstream. A liquid crystal display is composed of a liquid crystal display panel and a backlight module. Since the liquid crystal display panel itself does not emit light, the backlight module must be used as a light source to provide light so that the liquid crystal display panel can display images. Due to the characteristics of high brightness and small size, light emitting diodes have been gradually used in backlight modules, so that liquid crystal displays can be further developed towards the goal of lightness, thinness and high brightness.

FIG. 1 is a schematic partial cross-sectional view of a known side type backlight module. Referring to FIG. 1 , the backlight module 100 includes a support frame 110 , a circuit board 120 , a plurality of light emitting diodes 130 , and a light guide 140 . The support frame 110 can be divided into a side plate 112 and a bottom plate 114 connected to each other. The light guide plate 140 is disposed on the base plate 114 . The LEDs 130 are arranged on the circuit board 120 and electrically connected to the circuit board 120 . The circuit board 120 is fixed to the side plate 112 inside the support frame 110 by heat dissipation glue 150 , so that the light emitting diodes 130 form a line light source on the light incident side of the light guide plate 140 .

The LED 130 is driven through the circuit board 120 to emit light. After the light guide plate 140 converts the line light source formed by the light emitting diodes 130 into a surface light source, the light will pass through the optical film 160 and be guided into the liquid crystal display panel 170 , so that the liquid crystal display panel 170 presents images. As people's requirements for the brightness of the display continue to increase, the design of the light emitting diode 130 is gradually developed with high brightness, so the circuit board 120 needs to provide a larger current to drive the light emitting diode 130 . Since the LED 130 emits light, it also generates heat energy, and the heat energy passes through the circuit board 120 , the thermal paste 150 , and the side plate 112 of the support frame 110 in sequence before being dissipated into the air outside the backlight module 100 . Therefore, when the driving current given to the LED 130 is larger, the LED 130 will generate more heat energy, but the heat dissipation rate of this heat energy is far lower than the heat energy generation rate, so the heat energy will be accumulated in the backlight module 100, resulting in The luminous efficiency of the light emitting diode 130 is reduced and the circuit board 120 is damaged, thereby affecting the display quality of the liquid crystal display.

FIG. 2 is a partial cross-sectional schematic diagram of a known direct type backlight module. Referring to FIG. 2 , in the direct type backlight module 100′, the LEDs 130 are arranged in an array on the circuit board 120, and the circuit board 120 is disposed on the bottom plate 114 of the support frame 110. Similarly, in the backlight module 100', the thermal glue 150 is disposed between the bottom plate 114 and the circuit board 120, so as to fix the circuit board 120 in the supporting frame 110. It can be seen clearly from FIG. 2 that the heat energy generated by the LEDs 130 is still dissipated out of the backlight module 100' through the circuit board 120, the thermal paste 150 and the bottom plate 114 of the supporting frame 110 in sequence. It can be seen that, no matter the known backlight module is a side-lit type or a direct-lit type, there is a problem of poor heat dissipation.

In addition, when the light-emitting diode 130 is damaged due to improper assembly or use and needs to be replaced, since the circuit board 120 is fixed on the side plate 112 or the bottom plate 114 inside the support frame 110 through the heat dissipation glue 150, it is necessary to replace the backlight module 100 or the bottom plate 114. 100' of light source, the whole display needs to be disassembled, and it is possible to take out the circuit board 120 from the support frame. As a result, when a light source is damaged in the backlight module 100 or 100', the damaged light source cannot be easily replaced, resulting in high maintenance costs of the display.

Contents of the invention

In view of this, the object of the present invention is to provide a backlight module to solve the heat dissipation and assembly problems of the backlight module.

Another object of the present invention is to provide a liquid crystal display to solve the problem of poor display quality caused by poor heat dissipation of the backlight module.

To achieve the above or other objectives, the present invention provides a backlight module, which has a support frame and a light emitting diode module. The support frame has a plurality of through holes. The LED module includes at least one circuit board and a plurality of LEDs. The circuit board has a bearing surface, and the LEDs are arranged on the bearing surface and electrically connected to the circuit board. The light-emitting diodes of the light-emitting diode module pass through the through holes and are located in the support frame, and the circuit board is fixed outside the support frame with the bearing surface facing the support frame.

The invention provides a liquid crystal display, which includes a backlight module and a liquid crystal display panel. The backlight module has a support frame and a light emitting diode module. The support frame has a plurality of through holes. The LED module includes at least one circuit board and a plurality of LEDs. The circuit board has a bearing surface. The LEDs are arranged on the bearing surface and electrically connected to the circuit board. The light-emitting diodes of the light-emitting diode module pass through the through holes and are located in the support frame, and the circuit board is fixed outside the support frame with the bearing surface facing the support frame. The liquid crystal display panel is disposed above the backlight module.

In an embodiment of the present invention, the above-mentioned support frame includes a side plate and a bottom plate. The bottom plate is connected to the side plate, and the through hole is through the bottom plate or the side plate.

In an embodiment of the present invention, the above-mentioned backlight module further includes heat dissipation glue disposed between the supporting frame and the bearing surface of the circuit board.

In an embodiment of the present invention, the above-mentioned backlight module further includes a fixing part, which is suitable for fixing the circuit board outside the supporting frame.

In an embodiment of the present invention, the above-mentioned fixing elements are, for example, screws.

In an embodiment of the present invention, the above-mentioned backlight module further includes a light guide plate disposed in the support frame, and the light guide plate has a light-incident side, and the light-emitting diode module is disposed beside the light-incident side of the light guide plate .

In an embodiment of the present invention, the above-mentioned backlight module further includes a diffusion plate disposed between the support frame and the liquid crystal display panel, wherein the LED module is located between the diffusion plate and the support frame.

In an embodiment of the present invention, the above-mentioned backlight module further includes an optical film disposed on the support frame.

In an embodiment of the present invention, the above-mentioned optical film includes a diffusion film, a brightness enhanced film, a prism sheet or a combination of these films.

In an embodiment of the present invention, the aforementioned light emitting diodes are Lambertian type light emitting diodes or side-emitting type light emitting diodes.

In the present invention, the circuit board of the backlight module is exposed outside the supporting frame, so the heat energy generated by the light-emitting diodes can directly pass through the circuit board and be transferred to the air. In other words, the backlight module and the liquid crystal display of the present invention have a good heat dissipation effect, so the light emitting diodes can be driven with a large current to obtain high-brightness display quality without affecting the heat dissipation effect.

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

Description of drawings

Fig. 1 is a partial cross-sectional schematic diagram of a known side-illuminated backlight module

FIG. 2 is a schematic partial cross-sectional view of a known direct-lit backlight module.

FIG. 3 is a schematic cross-sectional view of the liquid crystal display in the first embodiment of the present invention.

FIG. 4 is an exploded schematic view of the supporting frame and the LED module according to the first embodiment of the present invention.

FIG. 5 is a schematic view of the light emitting diode module of FIG. 4 assembled on the supporting frame.

FIG. 6 is a front view of the supporting frame and the LED module in FIG. 5 along the Z direction.

FIG. 7 is a schematic partial cross-sectional view of a side-illuminated backlight module in a second embodiment of the present invention.

FIG. 8 is a schematic partial cross-sectional view of a liquid crystal display in a third embodiment of the present invention.

Explanation of reference signs

110, 410: support frame

112: side panel

114: bottom plate

120: circuit board

130: LED

140: light guide plate

150: heat dissipation glue

160: Optical film

170: Liquid crystal display panel

200: liquid crystal display

300: LCD display panel

400, 400a, 400’: backlight module

410: support frame

412: side panels

414: Bottom plate

416: Through hole

420: LED module

422: circuit board

422a: Bearing surface

422b: contact part

422c: screw lock hole

424: LED

426: pin

430: heat dissipation glue

440: Fixing parts

450: light guide plate

452: light incident side

454: exit surface

460: Optical film

470: diffuse board

480: reflective layer

Detailed ways

FIG. 3 is a schematic cross-sectional view of a liquid crystal display according to a first embodiment of the present invention. Referring to FIG. 3 , the liquid crystal display 200 includes a liquid crystal display panel 300 and a backlight module 400 , wherein the backlight module 400 is disposed under the liquid crystal display panel 300 to provide the surface light source required by the liquid crystal display panel 300 for displaying images. The backlight module 400 will be further described in detail below, so that those skilled in the art can clearly understand the present invention.

FIG. 4 is an exploded schematic diagram of the support frame and the LED module of the first embodiment of the present invention, and FIG. 5 is a schematic diagram of the assembly of the LED module in FIG. Front view in the Z direction. Please refer to FIG. 3 , FIG. 4 , FIG. 5 and FIG. 6 at the same time. The backlight module 400 has a support frame 410 and an LED module 420 . The support frame 410 includes a side plate 412 and a bottom plate 414 , the bottom plate 414 is connected to the side plate 412 , and the material of the support frame 410 is, for example, aluminum metal or galvanized steel plate and other metals with good heat transfer. The support frame 410 has at least one through hole 416 , and the through hole 416 passes through the side plate 412 . The light emitting diode module 420 includes at least one circuit board 422 and a plurality of light emitting diodes 424. The light emitting diodes 424 in this embodiment are, for example, Lambertian type light emitting diodes, and the circuit board 422 is, for example, aluminum or copper with good thermal conductivity. Metal material, which is a metal core circuit board (MCPCB). The circuit board 422 has a bearing surface 422 a on which the LED 424 is disposed and is electrically connected to the circuit board 422 through pins 426 .

It is worth mentioning that these LEDs 424 can be respectively configured on the circuit board 422 , as shown in FIG. 4 and FIG. 5 . Of course, these light emitting diodes 424 can also be configured on the same circuit board 422 , which is not limited in the present invention. In particular, the LED 424 passes through the through hole 416 and is located inside the support frame 410 , and the circuit board 422 is fixed outside the support frame 410 with the carrying surface 422 a facing the support frame 410 . As shown in Figure 6, the circuit board 422 of this embodiment has a contact portion 422b, and this contact portion 422b overlaps with the side plate 412 of the support frame 410, so the heat generated when the LED 424 emits light can be transferred to the support through the contact portion 422b. Frame 410, so that the circuit board 422 can quickly dissipate heat.

In this embodiment, the backlight module 400 is, for example, a side-illuminated backlight module. That is to say, the backlight module 400 further includes a light guide plate 450 disposed in the support frame 410 , and the light guide plate 450 has a light incident side 452 , and the LED module 420 is disposed beside the light incident side 452 of the light guide plate 450 .

In addition, in this embodiment, for example, the circuit board 422 is fixed outside the support frame 410 through the fixing member 440, and generally speaking, the more commonly used fixing member 440 is, for example, a screw, a buckle, a clip or an elastic sleeve, and the figure The fixing member 440 shown in 3 is a screw. In other words, the circuit board 422 of this embodiment is fixed on the side plate 412 of the supporting frame 410 by passing through the plurality of screw locking holes 422c of the circuit board 422 , and is exposed to the outside of the supporting frame 410 . Therefore, if the damaged LED module 420 is to be replaced, the LED module 420 can be directly disassembled from the support frame 410 without moving the light guide plate. Likewise, the steps of assembling the LED module 420 on the support frame 410 are simpler than known ones.

On the other hand, in this embodiment, heat dissipation glue 430 is also arranged between the bearing surface 422a of the circuit board 422 and the supporting frame 410 to further make the circuit board 422 and the side plate 412 of the supporting frame 410 tightly combined. In addition, the backlight module 400 also includes an optical film 460, which is disposed on the support frame 410, and the optical film 460 is, for example, a diffusion film, an enhancement film, a prism film or a combination of these films, while the liquid crystal display panel 300 It is disposed on the optical film 460 . In detail, if the optical film 460 is a brightness enhancement film, the brightness of the light emitted from the light guide plate 450 can be further improved. If the optical film 460 is a diffuser, the light emitted from the light guide plate 450 will pass through the optical film 460 to form a surface light source with relatively uniform brightness. If the optical film 460 is made of a prism sheet, it can be used to adjust the direction of the light emitted from the light guide plate 450 .

Please refer to FIG. 3 , FIG. 5 and FIG. 6 at the same time. After the current flows through the circuit board 422 to the light emitting diode 224 to drive it to emit light, the light emitted by the light emitting diode 424 will enter through the light incident side 452 of the light guide plate 450 , and then pass through the outgoing light. The output from the surface 454 enters the liquid crystal display panel 300 . The light emitting diode 424 also generates heat energy while emitting light, and the heat energy is transmitted to the circuit board 422 through the light emitting diode 424 . Here, since the circuit board 422 of the present invention is fixed outside the support frame 410, the heat energy transferred to the circuit board 422 can be directly dissipated from the circuit board 422 to the air outside the backlight module 400, and the heat energy of the LED 424 can also be With the aid of the support frame 410, the heat is dissipated into an environment with a lower ambient temperature. In detail, the heat energy may also be conducted from the supporting portion 422 b of the circuit board 422 to the supporting frame 410 , and then dissipated from the circuit board 422 and the supporting frame 410 to the outside of the backlight module 400 at the same time. Compared with the known backlight module 100, the heat energy generated by the light-emitting diode 424 in this embodiment can be dissipated directly from the circuit board 422 to the air without passing through components such as the heat-dissipating glue 430 and the side plate 412. The heat energy can be dissipated to the environment more quickly, and it has more heat dissipation paths. It can be seen that the backlight module of this embodiment has better heat dissipation efficiency than the known backlight module.

In addition, as shown in FIG. 6 , in order to increase the light utilization rate of the backlight module 400 , the backlight module 200 further includes a reflective layer 480 , and the reflective layer 480 is disposed on the part of the circuit board 422 exposed by the through hole 416 . In this embodiment, the reflective layer 480 is formed by white paint, which is a mixture of epoxy resin and pigment.

It is worth mentioning that, in order to make the achievable minimum thickness of the side-illuminated backlight module not limited by the size of the circuit board 422, the LED module 420 can also be arranged on the bottom plate 414 of the support frame 410, as shown in FIG. 7 shown. In this embodiment, the through hole 416 of the support frame 410 penetrates through the bottom plate 414 , and the LED 424 passes through the through hole 416 and is located in the support frame 410 . Here, the light emitting diode 424 is, for example, a side emitting type light emitting diode, so most of the light emitted by it can directly enter the light guide plate 450, and the light emitted by the light emitting diode 424 toward the support frame 410 can pass through. The support frame 410 with good reflective properties reflects it into the light guide plate 450 to improve light utilization efficiency.

It can be known from the above that the backlight module 400 a also exposes the circuit board 422 outside the supporting frame 410 , so the heat dissipation effect of the backlight module 400 of the previous embodiment is similar. That is to say, compared with the known backlight module 100, the backlight module 400a also has a better heat dissipation effect.

Although the liquid crystal display shown in FIG. 3 uses a side-lit backlight module as its light source, in other embodiments, the liquid crystal display of the present invention can also use a direct-lit backlight module as its light source. FIG. 8 is a schematic partial cross-sectional view of a liquid crystal display according to a third embodiment of the present invention. Please refer to FIG. 8, the difference between this liquid crystal display 500 and the liquid crystal display 200 of FIG. for explanation.

Please continue to refer to FIG. 8 , in the backlight module 400 ′, the LED module 420 is disposed on the bottom plate 414 of the supporting frame 410 . Wherein, the bottom plate 414 has at least one through hole 416 , the light emitting diode 424 passes through the through hole 416 and is located in the support frame 410 , and the circuit board 422 is fixed outside the support frame 410 with the carrying surface 422 a facing the support frame 410 . It is worth mentioning that the light emitting diode 424 is, for example, a Lambertian light emitting diode. That is to say, most of the light emitted by the light emitting diodes 424 is emitted upward, so that the backlight module 400' has a good light utilization efficiency.

In order to prevent the phenomenon of color unevenness (mura) of the liquid crystal display 500, the backlight module 400' of this embodiment has a diffuser plate 470 disposed between the light emitting diode module 420 and the liquid crystal display panel 300, so that the light emitting diodes 424 The light can be evenly diffused in the form of a surface light source, then pass through the optical film 460, and then be projected to the liquid crystal display panel 300, so that the liquid crystal display panel 300 displays images.

It should be noted that the heat generated by the LED 424 is first transferred to the circuit board 422 through the LED 424, and then directly dissipated from the circuit board 422 to the air outside the backlight module 400'. In addition, in the direct-lit backlight module 400' of the present invention, the heat energy of the light emitting diodes 424 can also be dissipated to an environment with a relatively low temperature through the assistance of the supporting frame 410. In detail, the heat energy can also be conducted from the circuit board 422 to the support frame 410, and then dissipated from the circuit board 422 and the support frame 410 to the outside of the backlight module 400'. Compared with the known direct-type backlight module 100', the backlight module 400' of this embodiment can not only dissipate heat energy to the environment more quickly, but also has more heat dissipation paths, so the backlight module 400' has an optimal cooling effect.

To sum up, in the backlight module of the present invention, a through hole is designed on the support frame, so that the light emitting diode can pass through the through hole and be located in the support frame when the circuit board is fixed outside the support frame, so as to avoid light loss of energy. Wherein, since the circuit board is exposed outside the support frame, the heat energy generated by the light emitting diodes can be quickly transferred to the outside of the backlight module. In this way, the liquid crystal display of the present invention can use a large current to drive the light-emitting diodes without worrying about the damage of the backlight module due to excessive temperature, so as to improve its luminous efficiency, and then make the images displayed by the liquid crystal display have high Brightness display quality.

In addition, in the present invention, the process of assembling the LED module to the support frame or disassembling the LED module from the support frame is simpler and time-saving than the known ones.

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, this The scope of protection of the invention should be defined by the claims.

Claims (20)

1. backlight module comprises:

Carriage has at least one through hole;

Light-emitting diode (LED) module comprises:

Circuit board has loading end; And

A plurality of light emitting diodes, be disposed on this loading end of this circuit board, and be electrically connected at this circuit board, and wherein these light emitting diodes are arranged in these through holes respectively and are positioned at this carriage, and this circuit board is to be fixed in outside this carriage towards carriage with this loading end.

2. backlight module as claimed in claim 1, wherein this carriage comprises:

Side plate; And

Base plate is connected in this side plate, and these through holes run through this base plate or this side plate.

3. backlight module as claimed in claim 1, wherein this circuit board has contact site, and is overlapping with this carriage.

4. backlight module as claimed in claim 1 also comprises thermal paste, is disposed between this loading end of this carriage and this circuit board.

5. backlight module as claimed in claim 1 also comprises fixture, is suitable for this circuit board is fixed in outside this carriage.

6. backlight module as claimed in claim 1 also comprises light guide plate, is disposed in this carriage, and wherein this light guide plate has the light inlet side, and this light-emitting diode (LED) module is disposed at by this light inlet side.

7. backlight module as claimed in claim 1 also comprises and disperses plate, is disposed on this carriage, and wherein this light-emitting diode (LED) module is dispersed between plate and this carriage at this.

8. backlight module as claimed in claim 1 also comprises blooming piece, is disposed on this carriage.

9. backlight module as claimed in claim 1, wherein this light emitting diode is lambert's type light emitting diode or led of side view type.

10. backlight module as claimed in claim 1 also comprises the reflection horizon, is disposed at the part that these through holes expose this circuit board.

11. backlight module as claimed in claim 10, wherein the material in this reflection horizon comprises epoxy resin and colorant mixture.

12. a LCD comprises:

Backlight module comprises:

Carriage has through hole at least;

Light-emitting diode (LED) module comprises:

Circuit board has a loading end;

A plurality of light emitting diodes, be disposed on this loading end of this circuit board, and be electrically connected at this circuit board, and wherein these light emitting diodes wear these through holes respectively and are positioned at this carriage, and this circuit board is to be fixed in outside this carriage towards carriage with this loading end; And

Display panels is disposed at this backlight module top.

13. LCD as claimed in claim 12, wherein this carriage comprises:

Side plate; And

Base plate is connected in this side plate, and these through holes run through this base plate or this side plate.

14. LCD as claimed in claim 12, wherein this circuit board has contact site, and is overlapping with this carriage.

15. LCD as claimed in claim 12, wherein this backlight module also comprises fixture, is suitable for this circuit board is fixed in outside this carriage.

16. LCD as claimed in claim 12, wherein this backlight module also comprises light guide plate, is disposed in this carriage, and wherein this light guide plate has the light inlet side, and this light-emitting diode (LED) module is disposed at by this light inlet side.

17. LCD as claimed in claim 12, wherein this backlight module also comprises and disperses plate, is disposed between this carriage and this display panels.

18. LCD as claimed in claim 12, wherein this backlight module also comprises blooming piece, is disposed between this carriage and this display panels.

19. LCD as claimed in claim 18, wherein this blooming piece comprises the combination of diffusion disk, brightening piece, prismatic lens or these diaphragms.

20. LCD as claimed in claim 12 also comprises the reflection horizon, is disposed at the part that these through holes expose this circuit board.

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