CN100547465C - Backlight - Google Patents

Abstract

The invention relates to a backlight source. The backlight source includes a light source, a backplane and a radiator, the light source is fixedly connected to the backplane, and the backplane is fixedly connected to the radiator. The backplane and the heat sink can be fixedly connected to each other through screws and nuts, screws and turned-out threads, and screws and threaded holes. The backlight source of the present invention can realize the fixed installation of the backplane and radiator of the large-size backplane source that needs heat dissipation, and the installation is simple and convenient.

Description

Backlight

technical field

The invention relates to a backlight source, in particular to a backlight source with heat dissipation function.

Background technique

Most of the existing flat panel displays are liquid crystal displays (Liquid Crystal Display, hereinafter referred to as LCD), which has the advantages of low power consumption, light weight and thin thickness. Since the liquid crystal itself does not emit light, the LCD needs to be displayed by the transmission or reflection of an external light source. Most of the existing LCDs are transmissive. For these transmissive LCDs, the backlight is an integral part of them, and the backlight provides the LCD with a light source. The commonly used cold cathode fluorescent tube (Cold Cathode Fluorescent Lamp, hereinafter referred to as CCFL) backlight uses CCFL as the light source, but the existing CCFL has the following problems:

1. In addition to its peak spectrum, CCFL will produce many unnecessary spectra, which will cause brightness deterioration and affect the high color reproduction of LCD. In LCD, the light emitted by the light source must pass through the LCD panel composed of red, green, and blue pixels. In order to obtain high color reproduction, it is required that the light from the LCD pixels can only have a narrow spectrum around the dominant wavelength.

2. The white light of CCFL is relatively cool, and the color rendering is relatively poor. The color produced by the light on the object is not as bright as the sunlight. For example, the CCFLs commonly used in current LCD TVs can only represent about 75% of the color range of the human eye.

3. CCFL is a tubular light source, and quite complex auxiliary components are required to evenly distribute the emitted light to every area of the panel. The thickness of the screen is also difficult to control, and with the increase of the panel, multiple light sources must be used, which further aggravates the complexity and cost of the design, and large-screen LCD TVs are more sensitive to this.

One method is to use light emitting diode (Light Emitting Diode, hereinafter referred to as LED) instead of CCFL as the light source. LED has the following advantages:

1. The LED spectrum is a narrow spectrum around the dominant wavelength.

2. The LED uses three primary colors of LED mixed with white light, which can better simulate sunlight and show natural colors, and the colors produced by irradiating objects or LCD colors are brighter and more realistic than CCFL.

3. LED is a planar light source. The most basic light-emitting unit is a square with a side length of 3-5mm after packaging. It is very easy to combine together to form a surface light source with a given area. It has good brightness uniformity. If it is used as a liquid crystal The design complexity and cost of auxiliary optical components required for the backlight source of TV are much lower than that of CCFL.

Therefore, LED backlights using LEDs as light sources have broad application prospects. However, the backplane of the existing CCFL backlight source is an integral structure, and the lamp tube is directly fixed on the backplane with a lamp tube bracket without a heat dissipation structure. Since the point light source of the LED is welded on the printed circuit board, the LED light source will Generate heat, which will increase the working temperature, and when the temperature of the LED chip exceeds a certain critical temperature, its luminous efficiency will be greatly reduced, which leads to a vicious circle and will inevitably shorten the life of the LED; the internal temperature of the backlight device is too high, often It will cause thermal stress deformation or yellowing of other components, and poor color mixing; if the internal temperature of the backlight is too high, it will also cause the LCD panel to overheat and shorten the display life of the LCD panel.

Contents of the invention

The present invention provides a backlight through an embodiment, which is used to solve the problem of heat dissipation of the LED backlight and the problem of installation and fixation of the heat sink of the backlight and the backplane.

The present invention provides following technical scheme through embodiment:

A backlight comprising:

A light source for generating backlight light;

A radiator connected to the light source for dissipating heat generated by the light source;

The backplane is connected with the heat sink.

The light source includes a light-emitting diode lamp group for generating light, and a printed circuit board on which the light-emitting diode lamp group is welded on one side and bonded or fixedly connected to the heat sink on the other side. The heat sink includes a base plate and fins connected to each other; the back plate includes a side wall and a bottom plate connected to each other, and the base plate and the bottom plate are fixedly connected. At least one heat dissipation hole is opened on the bottom plate, and the fins pass through the heat dissipation hole. The shape of the cooling hole is a chamfered or rounded rectangle. A first counterbore is opened on the base plate, a first through hole is opened on the bottom plate, the base plate and the bottom plate pass through, a screw passes through the first counterbore hole and the first through hole and is connected with a nut, Fixed connection. A first counterbore is opened on the base plate, a first threaded hole is opened on the base plate, the base plate and the base plate pass through, and a screw passes through the first countersink hole and is connected to the first threaded hole, Fixed connection. The threaded hole has an outwardly turned thread structure. A second countersink hole is opened on the base plate, a second threaded hole is opened on the base plate, the base plate and the base plate pass through, and a screw passes through the second countersink hole and is connected to the second threaded hole, Fixed connection. A second through hole is opened on the base plate, a second threaded hole is opened on the heat sink, the base plate and the base plate pass through, and screws pass through the second through hole and are connected to the second threaded hole to fix the connect. A screw sleeve is embedded in the second threaded hole.

Through the embodiments of the present invention, on the backlight that needs heat dissipation, the heat sink, the back plate, and related structures are designed, so that the heat sink and the back light can pass through countersunk holes, through holes, screws, and nuts, or sink The head holes, threaded holes and screws are fixedly connected, and the countersunk holes and threaded holes can be set on the radiator or on the back plate. Therefore, on the premise of ensuring that other related structures are not affected, different The fixed installation structure of the heat sink and the backplane in the production situation

Description of drawings

Figure 1a is a schematic diagram of a cross-sectional structure of a backlight source of the present invention;

Figure 1b is a schematic diagram of the relationship between the radiator, the screw and the printed circuit board in Figure 1a;

Figure 2a is a schematic diagram of the backplane structure in the backlight source of the present invention;

Fig. 2b is a schematic structural diagram of the radiator in the backlight of the present invention;

Fig. 2c is a schematic diagram of the threaded parts connecting the backplane and the heat sink in the backlight of the present invention;

Fig. 3 is a schematic diagram of the connection hole structure in the backlight of the present invention;

4 is a schematic cross-sectional structure diagram of a backlight embodiment of the present invention;

Fig. 5 is a schematic cross-sectional structure diagram of the second embodiment of the backlight source of the present invention;

6 is a schematic diagram of a three-sectional structure of a backlight embodiment of the present invention;

7 is a schematic diagram of a four-sectional structure of a backlight embodiment of the present invention;

8 is a schematic diagram of a five-sectional structure of a backlight embodiment of the present invention;

FIG. 9 is a schematic diagram of six cross-sectional structures of an embodiment of a backlight source according to the present invention.

Detailed ways

Fig. 1a is a schematic cross-sectional structure diagram of the backlight source of the present invention. As shown in Figure 1a, the backlight includes a backplane 1, a heat sink 2, and a light source 3; the light source 3 includes an LED lamp group 31 and a printed circuit board 32; the backplane 1 and the heat sink 2 pass through a screw 4 or a screw 4 The threaded holes are fixedly connected; the printed circuit board 32 and the heat sink 2 are bonded or fixedly connected by screws; the backplane 1 includes the side wall 11 and the bottom plate 12 ;

Fig. 1b is a schematic diagram of the relationship among the radiator, the screw and the printed circuit board in Fig. 1a. As shown in Figure 1b, the distance between the printed circuit board 32 and the substrate 21 is H1, the distance between the upper surface of the screw 4 and the upper surface of the substrate 21 is H2, and the thickness of the substrate 21 is H3; in practical applications, H1 The smaller the better, when H1=0, the heat dissipation effect is the best; ensure that H2>0, so that the connection between the backplane 1 and the radiator 2 does not affect the connection between the printed circuit board 32 and the substrate 21 on which the LED lamp group is welded. Tightly combined, but the larger H2 is, the smaller the connection part between screw 4 and substrate 21 will be, and the connection reliability will decrease. In practical applications, the value of H2 should be determined according to the thickness H3 of substrate 21. When H3 is large, H2 can be appropriately selected Larger, H3 hours, H2 must be as small as possible.

Fig. 2a is a schematic diagram of the structure of the backplane in the backlight source of the present invention. As shown in Figure 2a, the backplane includes a side wall 11 and a bottom plate 12; the bottom plate 12 is provided with cooling holes 121, and the number of cooling holes 121 can be one or multiple, and the bottom plate 12 is divided into a plurality of cooling holes. Multiple areas solve the problems of poor overall flatness performance of large-size backlight and difficult selection of radiator profiles; heat dissipation holes 121 are connected by ribs 122 on bottom plate 12; heat dissipation holes are rectangular to ensure that ribs 122 between heat dissipation holes 121 The strength is uniform. At the same time, the four corners of the heat dissipation hole 121 are processed into chamfered or rounded corners to avoid the four corners from being too fragile and ensure the strength of the four corners.

Fig. 2b is a schematic structural diagram of the heat sink in the backlight of the present invention. As shown in Figure 2b, the radiator includes a substrate 21 and fins 22; the number of radiators 2 is consistent with the number of cooling holes 121; Above, the two are connected at the rib 122; the outline structure of the fin 22 matches the structure of the cooling hole 121, and the outline of the fin 22 may be rectangular, or may have a chamfered or rounded structure.

Fig. 2c is a schematic diagram of the threaded parts connecting the backplane and the heat sink in the backlight of the present invention. As shown in FIG. 2 c , the threaded member 4 includes a screw 41 , a nut 42 and a screw sleeve 43 .

FIG. 3 is a schematic diagram of the connection hole structure in the backlight of the present invention. As shown in FIG. 3 , the connection hole includes a countersunk hole 51 , a through hole 52 , and a threaded hole 53 , and the countersunk hole 51 includes a countersunk portion 511 and a through hole portion 512 .

FIG. 4 is a schematic cross-sectional structure diagram of Embodiment 1 of the backlight source of the present invention. As shown in Figure 4, the base plate 21 of the heat sink is provided with a first counterbore, and the bottom plate 12 of the backplane is provided with a first through hole, and the positions of the first counterbore and the first through hole are corresponding; When the radiator is placed on one side of the backplane, the screw 41 is connected with the nut 42 placed on the other side of the backplane through the first counterbore and the first through hole, so that the radiator and the backplane are fixedly connected.

In this embodiment, the head of the screw is sunk by the countersunk hole, which ensures that the distance between the screw and the upper surface of the substrate is greater than zero. Therefore, the installation of the printed circuit board and other parts will not be affected. Through this embodiment, it is possible Realize the fixed installation and tight connection of the backplane and radiator without affecting the installation of other parts, because in this embodiment, the nuts are placed on the other side of the backplane, which will cause inconvenience in installation, so this embodiment is especially suitable for small Quantitative experiment process.

FIG. 5 is a schematic cross-sectional structure diagram of the second embodiment of the backlight source of the present invention. As shown in Fig. 5, different from Embodiment 1, the bottom plate 12 is provided with a first threaded hole. Since the bottom plate 12 is relatively thin, in practical applications, the first threaded hole is an outwardly turned hole thread structure 6. , the screw 41 is fixed on the hole-turning threaded structure 6.

In this embodiment, the nut in the embodiment is not needed, but the screw is directly placed on the turning thread, which solves the problem of inconvenient installation and slow assembly speed caused by the nut being arranged on the other side of the back plate in the first embodiment. It makes the installation easy, and because in this embodiment, a mold is required to process the turned-out screw thread, the cost will be increased in small batch production, so this embodiment is especially suitable for mass production.

FIG. 6 is a schematic diagram of three cross-sectional structures of an embodiment of a backlight source according to the present invention. As shown in Figure 6, the base plate 21 of the heat sink is provided with a second threaded hole, and the corresponding position on the bottom plate 12 of the back plate is provided with an inverted second counterbore. The other side fixes the screw 41 on the threaded hole of the radiator.

In this embodiment, by changing the installation method of the radiator and the backplane from the front-to-back installation method from the radiator to the backplane to the back-to-front installation method from the backplane to the radiator, the The tight installation of the radiator and the backplane solves the problem of inconvenient installation caused by the need for nuts in the first embodiment, the high cost of the mold required for processing the outward screw thread in the second embodiment, and the requirement for processing the counterbore on the radiator high question.

FIG. 7 is a schematic diagram of a four-sectional structure of an embodiment of a backlight source according to the present invention. As shown in FIG. 7 , the difference from the third embodiment is that the bottom plate 12 is provided with a second through hole. During installation, the screw 41 passes through the second through hole and is fixed on the second threaded hole of the radiator base plate 21 .

In this embodiment, the screws are placed on the outside of the backboard, and the method of non-sunk head inversion is adopted, which is different from the method of countersunk head inversion in embodiment 3. When the structure is required to be compact, the method of embodiment 3 should be used, and In the case where a compact structure is not required, the method of this embodiment can be applied, because it is easier to process a through hole than a counterbore.

FIG. 8 is a schematic diagram of a five-sectional structure of a backlight embodiment of the present invention. As shown in FIG. 8 , in this embodiment, a screw sleeve 43 is embedded in the second threaded hole of the third embodiment.

FIG. 9 is a schematic diagram of six cross-sectional structures of an embodiment of a backlight source according to the present invention. As shown in FIG. 9 , in this embodiment, a screw sleeve 43 is embedded in the second threaded hole of the fourth embodiment.

Embodiments 5 and 6 solve the problem that the thread strength of the radiator is weak and are not suitable for repeated disassembly and assembly, and achieve high connection strength between the backplane and the radiator, as well as strong shockproof and impact resistance.

The installation methods in the above embodiments can also be any two or multiple combinations of the above embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. A backlight source, characterized in that it comprises: A light source for generating backlight light; A radiator connected to the light source for dissipating heat generated by the light source; a backplane connected to the radiator; The light sources include: A light-emitting diode lamp group for generating backlight light; The printed circuit board is welded with the light-emitting diode lamp group on one side, and is bonded or fixedly connected to the heat sink on the other side. 2. The backlight according to claim 1, wherein the heat sink comprises a base plate and fins connected to each other; the back plate comprises a side wall and a base plate connected to each other, and the base plate and the base plate are fixedly connected. 3. The backlight according to claim 2, wherein at least one heat dissipation hole is opened on the bottom plate, and the fins pass through the heat dissipation hole. 4. The backlight according to claim 3, wherein the shape of the cooling hole is a rectangle with chamfered or rounded corners. 5. The backlight according to claim 2, wherein a first counterbore hole is opened on the base plate, a first through hole is opened on the base plate, the base plate and the base plate pass through, and screws pass through the base plate. The first counterbore and the first through hole are connected with a nut for fixed connection. 6. The backlight according to claim 2, wherein a first counterbore hole is opened on the base plate, a first threaded hole is opened on the base plate, the base plate and the base plate pass through, and screws pass through the base plate. The first counterbore is connected to the first threaded hole for fixed connection. 7. The backlight according to claim 6, characterized in that, the threaded hole has an outwardly turned hole thread structure. 8. The backlight according to claim 2, wherein a second countersink hole is opened on the base plate, a second threaded hole is opened on the base plate, the base plate and the base plate pass through, and screws pass through the base plate. The second counterbore is connected to the second threaded hole for fixed connection. 9. The backlight according to claim 2, wherein a second through hole is opened on the base plate, a second threaded hole is opened on the heat sink, the base plate and the base plate pass through, and the screws pass through the The second through hole is connected to the second threaded hole for fixed connection. 10. The backlight according to claim 8 or 9, wherein a screw sleeve is embedded in the second threaded hole.

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