CN1725082A - Direct Type Backlight Module - Google Patents

Abstract

The present invention discloses a direct-type backlight module, comprising a substrate, a nut, an auxiliary diffusion plate, a support column, a diffusion plate and at least one light-emitting diode. The nut is arranged on the substrate, the auxiliary diffusion plate is carried on the nut, and the support column comprises a cone column and a screw, the cone column comprises a cone top and a cone bottom, the screw protrudes from the cone bottom and passes through the auxiliary diffusion plate and is combined with the nut. Moreover, the diffusion plate is carried on the cone top. The light-emitting diodes are arranged under the auxiliary diffusion plate.

Description

Direct Type Backlight Module

technical field

The invention relates to a direct-down type backlight module, in particular to a direct-down type backlight module with a double-layer diffusion plate.

Background technique

Liquid crystal display (LCD) technology has been used in portable electronic products such as notebook computers, mobile phones, digital cameras, camcorders, and PDAs. Liquid crystal panel (LCD panel) is the most critical display component in this field, but it does not emit light by itself, and needs to be displayed through the setting of a backlight source. There are many kinds of backlight technologies now, and in large-size (about 20 inches or more) liquid crystal display products, a direct-type backlight module (bottom lighting module) is often used as the backlight of the liquid crystal panel. Due to the increasing development of electroluminescence technology, it has become a development theme to apply light emitting diode (Light Emitting Diode, LED) as the light source in the direct type backlight module.

Light-emitting diode light sources will have a breakthrough help for liquid crystal display products. The main reason is that the luminous efficiency of light-emitting diodes has been greatly improved. Even now, the luminous efficacy of light-emitting diodes is expected to keep pace with cold-cathode lamps. Of course, this is only in terms of the brightness of light-emitting diodes. If the characteristics of high response speed of light-emitting diodes are used to make red, blue, and green light sources of three kinds of light-emitting diodes switch and light in sequence at high speed, it can replace the high unit price color filter in the liquid crystal panel. From this point of view, the impact of light-emitting diode light sources on the future development trend of liquid crystal display products will be comprehensive and thorough.

Please refer to FIG. 1 , which is a side sectional view of a conventional backlight module. The backlight module 10 includes a backlight module base 12 , a circuit board 13 , at least one LED 14 , a reflection sheet 16 and a diffusion plate 18 . Wherein, the circuit board 13 is electrically connected to the LEDs 14 for controlling the LEDs 14 .

The circuit board 13 is disposed on the backlight module base 12 , the circuit board 13 has a plurality of holes 131 , and the upper half of the LED 14 has a light emitting portion 141 and the lower half has an LED base 142 . The light-emitting portion 141 is located on the circuit board 13 through the hole 131 . The LED base 142 is the main heat source of the LED 14 and is generally disposed under the circuit board 13 to prevent its heat energy from affecting the light efficiency of the backlight module 10 .

Moreover, the reflective sheet 16 is disposed on the circuit board 13 in an adhesive manner, and the reflective sheet 16 has a plurality of holes 161 corresponding to the plurality of holes 131 of the circuit board 13 . The plurality of holes 161 are also used to make the light-emitting portion 141 of the LED 14 protrude from the reflection sheet 16 . The light from the light emitting diodes 14 can be reflected upwards through the reflection sheet 16, so that the light can be fully utilized.

The light-transmitting diffuser plate 18 is erected on the backlight module base 12 by using its edge part. The difference between the refractive index of the material of the diffuser plate 18 and the air can make part of the light incident on the diffuser plate 18 produce total reflection, and the diffuser plate 18 and the reflection The plates 16 are reflected multiple times, so that the light mixing effect of the light emitted by each LED 14 can be improved, so that the light emitted from the diffuser plate 18 has uniform brightness and chromaticity.

Please refer to FIG. 2 . FIG. 2 is a side sectional view of a conventional LED backlight module with a double-layer diffuser. Since the light emitting diode 14 is side emitting (Side Emitting), most of its light will not be directly emitted upwards. In view of this, a light emitting diode backlight module 20 as shown in FIG. 2 has appeared in the prior art. The LED backlight module 20 is substantially the same as the LED backlight module 10 shown in FIG. 1 , the main difference is that an additional auxiliary diffuser 22 is added between the reflector 16 and the diffuser 18 .

The auxiliary diffuser 22 is erected on the stepped structure or the side wall around the backlight module base 12 by using its edge part, and its position is closer to the light emitting diodes 14, which makes the incident angle of the light emitted by the light emitting diodes 14 incident on the auxiliary diffuser 22 Larger, it is easier to produce large-angle reflections, and it helps light to go to the upper diffuser plate 18. Therefore, compared with the LED backlight module 10 in FIG. 1, the light mixing effect of the LED backlight module 20 in FIG. 2 will be better. For liquid crystal display products with higher requirements on the flatness of light, it is a better choice to use the LED backlight module 20 shown in FIG. 2 as the backlight module.

At present, most of the light-emitting diodes are used in small-sized liquid crystal display products, such as the backlight of mobile phone screens or car LCD screens. For larger-sized LCD screens, and even the application of light-emitting diode backlight in LCD TVs It is an important technology that R&D personnel are actively investing in development. When the size of the LCD screen increases, the area of the LED backlight module as its backlight also needs to be increased. In this case, the LED backlight module shown in Figure 1 and Figure 2 needs to increase the number of LEDs used. 14, and the area of the bottom plate of the frame 12, the area of the reflection sheet 16, the area of the diffusion plate 18 and the area of the auxiliary diffusion plate 22 all need to be increased.

However, as shown in FIG. 1 and FIG. 2, the reflection sheet 16, the diffuser plate 18 and the auxiliary diffuser plate 22 are only erected on the backlight module base 12 by using their respective edge portions. When the area is increased, the increased weight will The phenomenon that the diffuser plate 18 and the auxiliary diffuser plate 22 are dented. This concave phenomenon is an unacceptable shortcoming for liquid crystal display products that emphasize light uniformity, because once the flatness of the diffuser plate 18 and the auxiliary diffuser plate 22 is poor, the overall light uniformity of the LED backlight modules 10 and 20 will be serious. decline, and the larger the size of the liquid crystal display product, the more serious this shortcoming will be.

Therefore, under the two major trends of liquid crystal display products moving towards large size and LED light source gradually becoming the mainstream light source, for R&D personnel engaged in the field of LED light source, how to improve the diffusion plate and auxiliary diffusion in the LED backlight module Due to the concave defect of the board, it is an important direction for the current research and development to make the light emitting diode backlight module maintain the uniformity of its light.

Contents of the invention

The purpose of the present invention is to provide a backlight module with a supporting structure to support the auxiliary diffuser plate and the diffuser plate, so as to solve the problems in the prior art and improve the quality of the existing backlight module.

The invention provides a direct type backlight module. In one embodiment, the backlight module includes a backlight module base, a nut is arranged on the backlight module base; an auxiliary diffusion plate is carried on the nut; a circuit board It is arranged between the base of the backlight module and the auxiliary diffusion plate, and the circuit board has a hole for the nut to pass through; at least one light emitting diode is assembled on the circuit board; a support column includes a cone column and a screw , the cone column includes a cone top and a cone bottom, the screw protrudes from the cone bottom, passes through the auxiliary diffuser plate, and is combined with the nut; and a diffuser plate is carried on the cone top.

The present invention provides a direct type backlight module. In another embodiment, the backlight module includes a backlight module base; a circuit board is arranged on the backlight module base; at least one light emitting diode is assembled on the circuit board; a nut It is arranged on the circuit board; an auxiliary diffusion plate is carried on the nut; a support column includes a cone column and a screw, the cone column includes a cone top and a cone bottom, and the screw protrudes from the cone bottom , and pass through the auxiliary diffuser plate, and combined with the nut; and a diffuser plate, carried on the cone top.

The advantages and spirit of the present invention, as well as more detailed implementations, can be further understood through the following implementations and the accompanying drawings.

Description of drawings

Fig. 1 is a side sectional view of an existing backlight module;

Fig. 2 is a side sectional view of an existing light-emitting diode backlight module with a double-layer diffusion plate;

3 is a schematic diagram of an embodiment of a direct-type backlight module of the present invention;

4 is a schematic diagram of another embodiment of the direct type backlight module of the present invention;

5A-5E are schematic diagrams of other embodiments of screws and nuts in the present invention.

Detailed ways

Please refer to FIG. 3 , which is a schematic view of the first embodiment of the direct-lit backlight module of the present invention. The backlight module 30 includes a substrate 32 , a screw cap 33 , an auxiliary diffuser 34 , a support post 35 , a diffuser 36 and a light emitting diode 37 .

Wherein, the substrate 32 can be a circuit board (PCBA), which is electrically connected to the LEDs 37 and used to control the LEDs 37 . The circuit board is arranged on a backlight module base 39 , and is erected on the backlight module base 39 by its edge portion. Again, this circuit board has a plurality of holes 321, and the upper half of the light-emitting diode 37 has a light-emitting portion 371, and the lower half has a light-emitting diode base 372. The light-emitting diode base 372 is embedded in the hole 321, and the light-emitting portion 371 is exposed on the on this circuit board.

The nut 33 is disposed on the base plate 32 , and can be disposed on the base plate 32 by stamping or welding.

The auxiliary diffuser plate 34 is carried on the nut 33 . In practice, the edge portion of the auxiliary diffuser plate 34 can also be erected on the base 39 of the backlight module or can be supported on the peripheral walls.

The support column 35 includes a cone column 351 and a screw 352. The cone column 351 includes a cone top 3511 and a cone bottom 3512. The screw 352 protrudes from the cone bottom 3512. The screw 352 passes through the auxiliary diffuser plate 34 and is combined with the nut 33.

In one embodiment of the present invention, after the screw 352 is combined with the nut 33 , there is a predetermined distance between the cone bottom 3512 and the nut 33 , so that the cone bottom 3512 and the nut 33 will not clamp the auxiliary diffuser plate 34 tightly. Denting of the secondary diffuser plate 34 due to excessive clamping stress is avoided. Wherein, the predetermined distance is generally between 0.01mm and 5mm.

In addition, the diffusion plate 36 is carried on the cone top 3511 . In practice, the diffuser plate 36 can also be erected on the base 39 of the backlight module by using its edge portion, so as to enhance its assembly strength.

In one embodiment, a reflective sheet 38 is disposed on the substrate (circuit board) 32 , and the reflective sheet 38 has a hole 381 for receiving a nut. The cooperation between the hole 381 and the screw 352 can have a positioning function, so that the reflecting sheet 38 can be quickly arranged at a predetermined position during assembly. The reflective sheet 38 can be disposed on the surface of the substrate 32 in an adhesive manner. The light from the light-emitting diodes 37 can be reflected upwards through the reflection sheet 38, so that the light can be fully utilized.

The backlight module 30 of the present invention has a double-layer diffuser plate, including an auxiliary diffuser plate 34 and a diffuser plate 36 for enhancing the light mixing function of the LEDs.

The position of the auxiliary diffuser plate 34 is closer to the light emitting diode 37, which makes the incident angle of the light emitted by the light emitting diode 37 incident on the auxiliary diffuser plate 34, which is easier to produce large-angle reflection and better light mixing. Effect. The reflection sheet 38 , the auxiliary diffusion plate 34 and the diffusion plate 36 form two light mixing spaces, which can enhance the light mixing effect of the light emitted by each LED 37 , so that the light emitted from the diffusion plate 36 has uniform brightness and chromaticity.

Please refer to FIG. 4 , which is a schematic diagram of another embodiment of the direct-lit backlight module of the present invention. The backlight module 50 includes a substrate 59 , a screw cap 53 , an auxiliary diffuser 54 , a support post 55 , a diffuser 56 and a light emitting diode 57 .

In this embodiment, the substrate 59 refers to a back light module base (back bezel), wherein the back light module base is a metal plate. As shown in FIG. 4 , the nut 53 is disposed on the base plate 59 by stamping or welding; and the auxiliary diffuser plate 54 is carried on the nut 53 .

Moreover, the backlight module 50 further includes a circuit board 52 , the circuit board 52 is disposed between the auxiliary diffusion plate 54 and the substrate 59 , and is erected on the substrate 59 by its edge. A reflective sheet 58 may be disposed on the circuit board 52 . The circuit board 52 and the reflection sheet 58 define holes 581 for allowing the nuts 53 disposed on the substrate 59 to pass through the holes 581 to carry the auxiliary diffuser plate 54 .

The support column 55 includes a cone column 551 and a screw 552. The cone column 551 includes a cone top 5511 and a cone bottom 5512. The screw 552 protrudes from the cone bottom 5512. The screw 552 passes through the auxiliary diffuser plate 54 and is combined with the nut 53. The cone top 5511 carries the diffuser plate 56 .

It can be known from the above description that the auxiliary diffuser plate 54 and the diffuser plate 56 can provide a good support effect through the nut 53 and the support column 55 . Of course, the stepped structure of the backlight module base 59 or the surrounding side walls can also be used to support the edge portions of the auxiliary diffuser plate 54 and the diffuser plate 56 . To enhance the stability of the overall structure of the backlight module 50 .

In the light source part in the embodiment of FIG. 4 , the light-emitting diode 57 is assembled in another hole 521 of the circuit board 52, and the light emitted by the light-emitting diode 57 can obtain a good light mixing effect due to the auxiliary diffuser plate 54 and the diffuser plate 56, so as to The backlight module 50 can provide a backlight with good light mixing.

Please refer to FIG. 5A, which shows a support column 35 according to another embodiment of the present invention. In other variable embodiments of the present invention, the screw 352 shown in FIG. 3 can be replaced by a pin body 352' shown in FIG. 5A , the pin body 352' is a cylinder without threads. Whether it is the screw 352 in the foregoing embodiment, or the pin body 352' in this embodiment, it can be regarded as a male joint.

And the nut 33 shown in FIG. 3 can be replaced by a female coupling part 33' (as shown in FIG. 5A ) that does not have threads inside. The female coupling part 33' has a coupling hole 331' inside.

The pin body 352' and the female coupling part 33' of Fig. 5A can be combined in a tight-fitting manner. In practice, the female coupling part 33' is preferably made of metal, while the pin body 352' can be made of plastic material, which is injection molded. way of making.

Therefore, the diameter of the coupling hole 331' can be slightly smaller than or equal to the radius of the section of the male coupling part 352', so that the male coupling part 352' can be combined with the female coupling part 33' in a tightly fitting manner.

In another embodiment, the combination method of the pin body 352' and the female coupling part 33' may not use the above-mentioned tight fit method, but the aperture diameter of the coupling hole 331' is substantially equal to the radius of the section of the male coupling part 352' , and even make the diameter of the coupling hole 331' slightly larger than the radius of the section of the male coupling 352', so that the two can be combined, which is another embodiment of the present invention.

Considering that there should be a predetermined distance between the cone bottom 3512 and the female coupling part 33', which is generally between 0.01 and 5 mm, so as to avoid the depression of the auxiliary diffuser plate (the number 34 in Figure 3 or the number 54 in Figure 4), the combination can be made The hole 331' has a predetermined depth, and the predetermined depth of the coupling hole 331' is smaller than a predetermined length of the pin body 352', and the difference between the two is 0.01-5 mm, so that the combination of the cone bottom 3512 and the female can be maintained Predetermined spacing between pieces 33'.

Please refer to FIG. 5B to FIG. 5E , which are cross-sectional views of different embodiments along line A-A' of FIG. 5A . As shown in the figure, under the implementation method of combining the pin body 352' and the female coupling part 33' without screw mosquitoes, the cross-sectional shape of the pin body 352' and the coupling hole 331' can be circular, hexagonal, or square. Square, triangular or other shapes not shown in the drawing.

In view of the above embodiments, the present invention provides a backlight module conforming to the two trends of liquid crystal display products - 1) large size; 2) LED light source. Wherein, the concave defect of the diffuser plate and the auxiliary diffuser plate in the LED backlight module is improved, so that the LED backlight module can provide uniform light. And through the combination of nuts and screws, the present invention provides a support structure that is easy to assemble and locate, and it also has the function of supporting the auxiliary diffuser plate and the diffuser plate. Through the present invention, a backlight module with stable assembly and outstanding optical effect can be used by industry.

Although the present invention has been illustrated in conjunction with the above preferred examples, it is not intended to limit the spirit and entity of the present invention, and only limited to the above examples. Those skilled in the art can easily understand and use other components or methods to produce the same effect. Therefore, modifications made without departing from the spirit and scope of the present invention should be included in the claims.

Claims (17)

1. A direct type backlight module, comprising: Substrate; a female coupling, arranged on the substrate; an auxiliary diffusion plate, carried on the female coupling; The support column includes a cone column and a male coupling, the cone column includes a cone top and a cone bottom, the male coupling protrudes from the cone bottom, passes through the auxiliary diffuser plate, and is coupled to the female coupling; a diffuser plate carried on the cone; and At least one LED is arranged under the auxiliary diffusion plate. 2. The direct type backlight module as claimed in claim 1, wherein the substrate is a circuit board, and the LED is assembled on the circuit board. 3. The direct type backlight module as claimed in claim 2, further comprising a backlight module base disposed under the circuit board. 4. The direct type backlight module as claimed in claim 2, further comprising a reflection sheet disposed on the circuit board. 5. The direct type backlight module as claimed in claim 4, wherein the reflective sheet has a hole for receiving the female coupling member. 6. The direct type backlight module as claimed in claim 1, wherein the substrate is a backlight module base. 7. The direct type backlight module as claimed in claim 6, wherein the base of the backlight module is made of metal. 8. The direct type backlight module as claimed in claim 6, further comprising a circuit board, the LED is assembled on the circuit board, the circuit board is arranged between the auxiliary diffusion plate and the substrate, and the circuit board has a hole to Accommodates the female coupling. 9. The direct type backlight module as claimed in claim 8, further comprising a reflective sheet disposed on the circuit board. 10. The direct type backlight module as claimed in claim 9, wherein the reflective sheet has a hole for receiving the female coupling part. 11. The direct type backlight module as claimed in claim 1, wherein the cone bottom and the female coupling part have a predetermined distance between 0.01mm and 5mm. 12. The direct type backlight module as claimed in claim 1, wherein the auxiliary diffuser plate has a hole for receiving the male coupling part. 13. The direct-type backlight module as claimed in claim 1, wherein the male coupling member is a screw or a pin. 14. The direct type backlight module as claimed in claim 1, wherein the female coupling part is a screw cap. 15. The direct type backlight module as claimed in claim 1, wherein the female coupling part has a coupling hole for coupling with the male coupling part, and the cross-sectional shape of the male coupling part and the coupling hole can be circular, hexagonal , square or triangle. 16. A direct-lit backlight module, comprising: Backlight module base; A screw cap is arranged on the base of the backlight module; an auxiliary diffusion plate, carried on the nut; The circuit board is arranged between the base of the backlight module and the auxiliary diffusion plate, and has a hole for the nut to pass through; at least one light emitting diode assembled on the circuit board; The support column includes a cone column and a screw, the cone column includes a cone top and a cone bottom, the screw protrudes from the cone bottom, passes through the auxiliary diffuser plate, and is combined with the nut; and The diffusion plate is carried on the cone top. 17. A direct-lit backlight module, comprising: backlight module base, The circuit board is arranged on the base of the backlight module; at least one light emitting diode assembled on the circuit board; a nut arranged on the circuit board; an auxiliary diffusion plate, carried on the nut; The support column includes a cone column and a screw, the cone column includes a cone top and a cone bottom, the screw protrudes from the cone bottom, passes through the auxiliary diffuser plate, and is combined with the nut; and The diffusion plate is carried on the cone top.

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