KR101319495B1 - Back light structure and liquid crystal display device thereby - Google Patents

Abstract

The present invention provides a backlight structure and a liquid crystal display device having the same to prevent a color shift caused by a high heat generation compared with light efficiency and a rise in temperature when using light emitting means such as an LED as a light emitting source. The present invention relates to a liquid crystal display device comprising: a lower cover having a plurality of holes formed in an array at a bottom thereof; A metal PCB fastened to a rear surface of the lower cover, wherein at least one light emitting means having a light emitting part directed toward the inside through a hole of the lower cover; A reflection plate attached to the lower cover and having a plurality of holes formed in an array; And a liquid crystal panel stacked on the reflective plate at a predetermined interval.

Light emitting means, heat dissipation structure

Description

BACK LIGHT STRUCTURE AND LIQUID CRYSTAL DISPLAY DEVICE THEREBY}

1 is a cross-sectional view of a direct type liquid crystal display device according to the related art.

FIG. 2 shows a metal PCB arranged on the bottom cover shown in FIG. 1. FIG.

3A is a cross-sectional view of a direct type liquid crystal display device according to the present invention.

FIG. 3B is a perspective view of the lower cover shown in FIG. 3A

3C is a perspective view of the metal PCB shown in FIG. 3A

4 is a view showing a lower cover according to another embodiment of the present invention.

5 illustrates a metal PCB according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

130: lower cover 132: screw

134: metal PCB 136: light emitting means

138: reflector plate 142: diffuser plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight structure and a liquid crystal display device having the same, and more particularly, to a color shift caused by a high heat generation compared to light efficiency and a temperature rise according to the use of light emitting means such as an LED as a light emitting source. In order to prevent the phenomenon, the light emitting means is fixed to a metal PCB (Metal Printed Circuit Board) consisting of an array on the back of the lower cover to smoothly dissipate heat generated in the light emitting means.

BACKGROUND ART A direct type back-light used in a liquid crystal display of a large-sized model generally reflects light from a cold cathode fluorescent lamp to a liquid crystal panel on the front side from a reflector. In addition, a milky white scattering plate is additionally disposed in the light reflection path, so that light having a locally uniform illuminance is illuminated on the liquid crystal display. However, such a method has a problem of bringing a liquid crystal display to a large and complicated model due to problems such as the backlight thickness of the display.

In recent years, as a surface light source device, it is a two-pole device that emits light only when a current passes, and the backlight is thinned by using a light emitting diode (LED) which has characteristics such as fast response speed, low power consumption, and semi-permanent life. At the same time, brightness is improved. Above all, the next-generation LCD which can replace the cold cathode tube backlight device can be reproduced with natural color and high quality image compared to the existing cold cathode tube, and it can be replaced with the cold cathode tube backlight device due to the recognition that it is an eco-friendly product that does not use mercury. The core parts are also good.

Next, the liquid crystal display device having the conventional direct type LED backlight device will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, the liquid crystal display device has a main support 50 made of synthetic resin or SUS STEEL having a substantially rectangular frame shape as a reference, and a backlight device (not shown) (Unrepresented), and the liquid crystal panel 10 is stacked and fastened in the upper part. An upper cover 60 capable of fixing both covers the front edge of the liquid crystal panel 10 and is assembled and fastened to the main support 50 and the lower cover 30.

First, in the case of the direct type LED backlight for providing light to the liquid crystal panel, the LED array 36 in which at least one string of LEDs mounted on the lower cover 40 and emitting light is formed in series. And a plurality of PCBs (Printed Circuit Board) 34 having the LED array 36 on the front surface and driving the LED array 36 while driving up and down, and a lower front surface of a region in which the PCB 34 is driven. A reflecting plate 32 formed on the upper surface of the LED array 36 and a diffuser plate 42 that mitigates the non-uniformity of the light generated from the LED array 36, and the light passing through the diffuser plate 42. It comprises a prism sheet 44 to increase the brightness of the protection sheet 46 and to protect the prism sheet 44 and to increase the viewing angle.

Above all, in the above configuration, the reflector plates 32 and 38 may include the reflector plate 32 formed on the lower front surface of the region in which the PCB 34 is driven, and the LED array formed of at least one string ( 36 is provided with a reflector plate 38 formed on one PCB 34, where the reflector plate 38 formed on one PCB 34 forms a hole in an area corresponding to the LED. do.

When the backlight device is primarily completed as described above, the main support 50 made of a synthetic resin or sus steel mold having a substantially rectangular frame shape is fastened, and then the liquid crystal panel 10 is loaded on the upper side. do. Of course, the liquid crystal panel 10 here is composed of a thin film transistor array substrate and a color filter substrate bonded together, and liquid crystal injected therebetween.

FIG. 2 is a plan view illustrating a plurality of PCBs 34 arranged and fixed on the lower cover 30 as shown in FIG. 1. Conventionally, about 8 PCB arrays are used based on 32-inch LCD display, but due to the high temperature heat generation problem related to the LEDs fixed on the PCB, the PCB is separated from the back. There is a trend to use metal PCB formed by coating the metal material. Although not shown in the drawing, the metal PCB 34 is fixed on a metal bar such as aluminum and fastened on the lower cover 30.

On the other hand, although not separately shown in the drawing in addition to the bottom of the cover 30, a heat sink (heat sink) is additionally attached as a heat dissipation means to use a structure that emits heat generated from the LED to the outside.

However, in such a structure, air gaps exist between the lower cover 30 and the internal metal PCB, and the lower cover 30 and the heat sink are not completely adhered to each other. It acts as a heat resistor and inhibits a smooth heat dissipation function.

In addition, in order to dissipate the heat generated from the junction of the LED, which is a heat source, to the outside of the backlight, the metal PCB, the lower cover, and the heat sink itself become a kind of heat resistance, so that a large amount of metal material is added, and the thicker the thickness, the lower the heat radiation. do.

Therefore, the present invention does not separately attach a heat sink used as a conventional heat dissipation means, but instead forms a plurality of holes forming an array in the bottom surface of the lower cover, and the lens portion of the light emitting means fixed on the metal PCB The purpose is to improve the above problems by fastening the metal PCB to the back of the lower cover to face the hole.

And the achievement of this object can be further embodied through the present invention. That is, the liquid crystal display according to the present invention comprises: a lower cover having a plurality of holes formed in an array on a bottom surface thereof; At least one light emitting means in which the light emitting portion is directed inwards through the hole of the lower cover is arranged and fixed in series, and a fastening hole for screwing is formed at at least one edge thereof, and a rear surface of the lower cover through the fastening hole. A metal PCB fastened from; A reflection plate attached to the lower cover and having an array of a plurality of holes corresponding to the holes of the lower cover; And a liquid crystal panel disposed spaced apart from the reflective plate by a predetermined interval, wherein each of the plurality of holes of the lower cover is formed to have a length corresponding to the metal PCB and a width corresponding to the light emitting region.

In addition, the backlight structure of the liquid crystal display device according to the present invention includes a lower cover formed of an array of a plurality of holes on the bottom surface; At least one light emitting means in which the light emitting portion is directed inwards through the hole of the lower cover is arranged and fixed in series, and a fastening hole for screwing is formed at at least one edge thereof, and a rear surface of the lower cover through the fastening hole. A metal PCB fastened from; And a reflecting plate attached to the lower cover and formed with an array of a plurality of holes corresponding to the holes of the lower cover, wherein each of the plurality of holes of the lower cover has a length corresponding to the metal PCB and the light emission. It is characterized in that it is formed to have a width corresponding to the portion.

Then, with respect to the above configuration will be described in detail with reference to the drawings. 3A is a cross-sectional view illustrating a configuration of a liquid crystal display device according to the present invention. As can be seen in the figure, the bottom of the back cover 130 is upper and lower sides of the lower cover 130 based on the main support 150 made of a synthetic resin or a stainless steel (SUS STEEL) mold having a substantially rectangular frame shape. The device (not shown), and the upper portion of the liquid crystal panel 110 is sequentially loaded and fastened. Thereafter, an upper cover 160 capable of fixing all of them covers the front edge of the liquid crystal panel 110 and is assembled and fastened to the main support 150 and the lower cover 130.

First, the lower cover 130 according to the present invention has a hole having a width corresponding to the light emitting portion so as to facilitate the input of the light emitting means 136 such as, for example, a light emitting diode (LED) on the bottom surface thereof. At least one 130a) is formed. Of course, the lower cover 130 made of iron (Fe) or the like is manufactured by a sheet metal forming method using a press. Other details will be discussed later.

In addition, a plurality of light emitting means 136 is stringed, that is, a metal PCB 134 is fastened in series to the rear surface of the lower cover 130 where the hole is formed. Of course, the light emitting means 136 here is directed toward the inside of the lower cover 130 as can be seen in the figure. The lower cover 130 and the metal PCB 134 are fastened to the lower cover 130 by using a separate metal bar such as aluminum (Al) to which the metal PCB 134 is attached. Holes are formed at the edges to thereby fasten screws 132.

On the other hand, the light emitting means 136 here, for example, in the case of LED, may be a mixture of red, green, and blue LEDs to produce white light, on the other hand, As such, it is also preferable that the above R, G, B LEDs are formed of a silicon material as one cluster on the metal PCB 134 to generate white light.

As described above, after the at least one metal PCB 134 to which the plurality of light emitting means 136 is fixed by a string is fastened to the rear surface of the lower cover 140 through an aluminum metal bar, the lower cover 140 is then Inside it is attached a reflector 138 for reflecting the light emitted from the light emitting means 136 to the front, of course, the reflector 138 here also corresponds to the individual LED or cluster already mentioned Since a hole is formed in the portion to be in close contact with the lower cover 130, the light from the light emitting unit 136 may be efficiently reflected to the front surface.

Now, when the attachment process of the reflecting plate 138 as described above is completed, the diffusion plate 142 is loaded in order to alleviate the non-uniformity of the light emitted from the light emitting means 136, the diffusion plate 142 Above, the prism sheet 144 which increases the brightness of light is loaded again. Then, the protective sheet 146 is sequentially loaded to protect the prism sheet 144 and increase the viewing angle.

After the fastening of the primary backlight device is completed as described above, the main support 150 made of a synthetic resin or sus steel mold having a substantially rectangular frame shape is fastened, and then the liquid crystal panel 110 is upward. ) Is loaded. Of course, the liquid crystal panel 10 here is a thin film transistor array substrate and a color filter substrate bonded to each other, and includes a liquid crystal injected therebetween.

After that, the upper cover 160 that can fix all of its components covers four edges of the liquid crystal panel 110 and is assembled and fastened to the main support 150 and the lower cover 130.

Then, the lower cover 130, 230 and the metal PCB (134, 234) according to the present invention will be described in more detail. 3B is a perspective view of the lower cover 130 shown in FIG. 3A. As shown in the drawing, the bottom surface of the lower cover 130 forms a plurality of holes 130a forming an array in parallel with each other. More precisely, when referring to a 32-inch LCD display, it is preferable that approximately eight holes 130a are formed in an array, but the present invention is not necessarily limited thereto. For example, one large hole may be formed in the left and right centers of the lower cover 130, respectively, or one large hole may be formed without removing the middle area.

In addition, in the drawing, the width W of the hole 130a is formed so that the light emitting means 136 on the metal PCB 134 fastened from the rear surface of the lower cover 130 may be introduced therein. It should be formed to be almost the same as the width of the light receiving portion consisting of only the body portion or the lens of 136, which is considered to be determined by the thickness of the lower cover 130.

3C is a perspective view of the metal PCB 134 fastened to the rear surface of the lower cover 130 shown in FIG. 3A. As can be seen in the figure, a plurality of light emitting means 136 are arranged and fixed in a string on a metal PCB 134 of a suitable size, the group of light emitting means 136 arranged in the string is the lower cover 130 It is injected into the hole (130a) formed on the bottom surface of the metal PCB 134 is fastened to the lower cover 130 by using a screw or the like in the fastening hole (134a) formed on both sides of the edge. In addition, an electrode portion 134b for applying a voltage from a separate driver (not shown) is formed at one edge of the front portion of the metal PCB 134 so that the light emitting means 135 operates.

4 is a view showing a lower cover 230 according to another embodiment of the present invention. Here, the first sheet metal of the lower cover 230 may be manufactured in consideration of the number of light emitting means 136 fastened from the rear surface thereof, and the formation width of the hole 230a is also the same as mentioned above. In other words, the width of the body portion or the light receiving portion of the light emitting means 136 to be injected from the rear surface of the lower cover 230 is formed to be substantially the same.

5 illustrates a metal PCB 234 according to another embodiment of the present invention. This is a view of the metal PCB 134, which has already been described with reference to FIG. 3A, in another aspect. Here, a plurality of arrays are formed on the large-scale metal PCB 234 to fix the light emitting means 236, and the string unit. As the electrode portion 234b is formed at one side edge, the operation may be easier than that of the metal PCB 134 in which the light emitting means 136 is fixed to one string as shown in FIG. 3A. When a voltage is applied from the wire (not shown), the wire processing becomes relatively simple.

On the other hand, based on the contents so far, the metal PCB (134, 234) shown in Figure 3c or 5 can be applied to the present invention by selecting the lower cover (130, 230) shown in Fig. 3a or 4 In view of the highly developed sheet metal forming technology, the light emitting means 136 and 236 are fixed to the holes 130a and 230a of the lower cover 130 and 230 in units of strings on the metal PCBs 134 and 234. You will be able to commit with high precision.

On the other hand, the metal PCBs 134 and 234 shown in FIGS. 3C and 5 may be fastened to the inside of the lower covers 130 and 230 according to the present invention. In this case, a substantial portion of the metal PCBs 134 and 234 fastened to the inner side of the lower covers 130 and 230 may come into contact with the outside air at the rear surfaces of the lower covers 130 and 230, thereby improving the heat dissipation. Seems to be.

As a result of the configuration up to now, the backlight structure and the liquid crystal display device having the same according to the present invention maximize the heat dissipation characteristics by minimizing a heat resistance path such as, for example, a heat sink, from the heat of the light emitting means. As a result, it is easy to improve the light efficiency such as the junction temperature of the light emitting means is reduced and to ensure the reliability of the lifetime. In addition, since the heat dissipation means such as a separate heat sink is unnecessary, there is an effect of reducing the material cost and the like.

Claims (18)

A lower cover having a plurality of holes formed in an array at a bottom thereof; At least one light emitting means whose light emitting portion is directed inwardly through the hole of the lower cover is arranged and fixed in series, and a fastening hole for screwing is formed at at least one edge thereof, and a rear surface of the lower cover through the fastening hole. A metal PCB fastened from; A reflection plate attached to the lower cover and having an array of a plurality of holes corresponding to the holes of the lower cover; And It includes a liquid crystal panel mounted on the reflecting plate spaced apart at regular intervals, And each of the plurality of holes of the lower cover has a length corresponding to a length of the metal PCB and a width corresponding to a width of the light emitting means. The liquid crystal display device according to claim 1, wherein the light emitting means is a red (R), green (G), or blue (B) LED. The liquid crystal display device according to claim 1, wherein the light emitting means is a cluster comprising red (R), green (G), and blue (B) LEDs. The liquid crystal display device according to claim 1, wherein the light emitting means is an LED of a bag (W). delete The liquid crystal display device of claim 1, wherein the metal PCB further comprises an electrode part configured to receive a voltage at at least one edge of a front surface of the metal PCB. A lower cover having a plurality of holes formed in an array at a bottom thereof; At least one light emitting means whose light emitting portion is directed inwardly through the hole of the lower cover is arranged and fixed in series, and a fastening hole for screwing is formed at at least one edge thereof, and a rear surface of the lower cover through the fastening hole. A metal PCB fastened from; And A reflection plate attached to the lower cover and formed with an array of a plurality of holes corresponding to the holes of the lower cover; And each of the plurality of holes of the lower cover has a length corresponding to a length of the metal PCB and a width corresponding to a width of the light emitting means. The backlight structure of a liquid crystal display device according to claim 7, wherein the light emitting means is a red (R), green (G), or blue (B) LED. The backlight structure of a liquid crystal display device according to claim 7, wherein the light emitting means is a cluster comprising red (R), green (G), and blue (B) LEDs. The backlight structure of a liquid crystal display device according to claim 7, wherein the light emitting means is an LED of a back (W). delete 8. The backlight structure of claim 7, wherein the metal PCB further includes an electrode unit configured to receive a voltage at at least one edge of a front surface of the metal PCB. 9. A liquid crystal panel; Light emitting means for providing light to the liquid crystal panel; A metal hole in which a fastening hole for screwing is formed on at least one edge, and the light emitting means is mounted; A plurality of holes are formed on a bottom surface of the metal PCB to have a length corresponding to the length of the metal PCB and a width corresponding to the width of the light emitting means, and are fastened to the metal PCB through the fastening hole, wherein the light emitting means is the hole. Liquid crystal display comprising a lower cover facing the inside through, at least a portion of the metal PCB exposed on the back. The liquid crystal display device according to claim 13, wherein the light emitting means is a red (R), green (G), or blue (B) LED. The liquid crystal display device according to claim 13, wherein the light emitting means is a cluster comprising red (R), green (G), and blue (B) LEDs as one. The liquid crystal display device according to claim 13, wherein the light emitting means is an LED of a bag (W). delete The liquid crystal display of claim 13, wherein the metal PCB further includes an electrode unit configured to receive a voltage at at least one edge of a front surface of the metal PCB.

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