KR20120052694A - Liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display device is provided to arrange an LED(Light Emitting Diode) PCB(Printed Circuit Board) in parallel with liquid crystal panels which configures a light source, thereby forming LED devices arranged on an LED PCB in a side view type. CONSTITUTION: A light source(130) provides light to a light guide plate. A first optical member(140) is located on the light guide plate. A first liquid crystal panel(160) is located on the first optical member. A second optical member(150) is located on a lower part of the light guide plate. A second liquid crystal panel(170) is located on a lower part of the second optical member.

Description

Liquid Crystal Display

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of improving the heat dissipation effect of a double-sided liquid crystal display device.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, the demand for light and thin flat panel display devices can be gradually increased. Liquid crystal display (LCD), plasma display panel (PDP), organic light emitting diode (OLED), etc. are being actively researched as such flat panel display devices. BACKGROUND ART Liquid crystal display devices, which are easy to drive and easily implement high image quality, have been in the spotlight.

The liquid crystal display classified into a light receiving display device may include a backlight unit disposed below the liquid crystal panel to provide light to the liquid crystal panel in addition to the liquid crystal panel displaying an image.

Recently, in addition to a single-sided liquid crystal display device that implements light in only one direction, a double-sided liquid crystal display device that implements images on both sides has been developed. In the double-sided liquid crystal display, liquid crystal panels are positioned on both sides of the light guide plate for guiding light provided from the light source, thereby realizing images on both sides.

1 is a view showing a conventional double-sided liquid crystal display device.

Referring to FIG. 1, the conventional double-sided liquid crystal display device 10 includes a light guide plate 11 for guiding light, a light source 12 for providing light to the light guide plate 11, and optical members positioned at upper and lower portions of the light guide plate 11, respectively. 16a and 16b, and liquid crystal panels 17a and 17b respectively positioned on upper and lower portions of the optical members 16a and 16b, and source PCBs 18a and 18b and optical members 16a and 16b respectively connected to the liquid crystal panels 17a and 17b. And panel guides 19a and 19b for fixing the liquid crystal panels 17a and 17b, and cases 20a and 20b for housing them.

The light source 12 is composed of a LED PCB 14, a plurality of LED elements 13 arranged on the LED PCB 14, LED elements that provide a large amount of light due to the characteristics of the double-sided liquid crystal display device ( In 13) a lot of heat is generated. To this end, the conventional liquid crystal display 10 forms an aluminum extrusion bar 15 on the rear surface of the LED PCB 14, thereby fixing them while releasing heat generated from the LED elements (13).

However, the conventional double-sided liquid crystal display device has a problem in that the heat dissipation effect is insufficient since the heat emitted from the LED elements are emitted only from the aluminum extrusion bar 15.

Accordingly, the liquid crystal display device of the present invention provides a liquid crystal display device capable of efficiently dissipating heat emitted from the LED elements.

In order to achieve the above object, a liquid crystal display according to an embodiment of the present invention is a light guide plate for guiding light, a light source for providing light to the light guide plate, a first optical member located on the light guide plate, the first optical A first liquid crystal panel positioned on the member, a second optical member positioned below the light guide plate, and a second liquid crystal panel positioned below the second optical member, wherein the light source includes: an LED element and the LED element; Including an LED PCB, the LED PCB may be disposed in parallel with the first liquid crystal panel.

The LED device may be a side view type.

The display device may further include an upper panel guide fixing the first optical member and the first liquid crystal panel, and a lower panel guide fixing the second optical member and the second liquid crystal panel.

The LED PCB may be positioned and fixed between the upper panel guide and the lower panel guide.

The light source may include an LED PCB, a copper layer positioned on the LED PCB, and LED elements arranged on the copper layer.

The width of the LED PCB may be 11 to 15mm.

The liquid crystal display according to an exemplary embodiment of the present invention arranges an LED PCB constituting a light source in parallel with the liquid crystal panels, and forms LED elements arranged on the LED PCB in a side view type, thereby generating heat generated in the LED elements. There is an advantage that can be released efficiently.

1 is a view showing a conventional double-sided liquid crystal display device.
2 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.
3 is a cross-sectional view taken along line II ′ of FIG. 2;
4 is a cross-sectional view showing a light source according to an embodiment of the present invention.
5 is a plan view showing a light source according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line II ′ of FIG. 2.

2 and 3, the liquid crystal display 100 according to an exemplary embodiment of the present invention may include a light guide plate 120, a light source 130 provided on at least one side of the light guide plate 120, and a light guide plate 120. The first optical member 140 is positioned, and the first liquid crystal panel 160 is positioned on the first optical member 140. The second optical member 150 is disposed below the light guide plate 120, and the second liquid crystal panel 170 is disposed on the second optical member 150.

The upper panel guide 180a fixing the first optical member 140 and the first liquid crystal panel 160 is positioned, and the lower panel guide fixing the second optical member 150 and the second liquid crystal panel 170. 180b is located.

In more detail, the upper cover 110a and the lower cover 110b serve as a casing of the liquid crystal display device 100 to provide the light guide plate 120, the light source 130, and the first and second optical members 140 and 150. ) And the first and second liquid crystal panel 160 and the upper and lower panel guides 180a and 180b.

The upper cover 110a and the lower cover 110b may have a rectangular frame shape and may be coupled to each other.

The light guide plate 120 guides the light incident from the light source 130 to change the line light source into a surface light source. The light guide plate 120 is made of PMMA (PolyMethylMethAcrylate) having excellent total reflectance. Then, the light guide plate 120 provides the light of the light source to the top or bottom.

For example, at least one light source 130 may be formed on one side of the light guide plate 120 in the long axis direction of the light guide plate 120, or one or more light sources 130 may be formed on each side of the light guide plate 120. The light emitted from the light source 130 may be incident directly into the light guide plate 120.

The first optical member 140 and the second optical member 150 positioned on one surface and the other surface of the light guide plate 120 serve to diffuse or collect light emitted from the light guide plate 120.

The first optical member 140 and the second optical member 150 are composed of diffusion sheets 141 and 151 and light collecting sheets 142 and 152, respectively. The diffusion sheets 141 and 151 diffuse the light incident from the light guide plate 120 and serve to make the luminance of the light uniform. In addition, the light collecting sheets 142 and 152 may be at least a prism sheet, a micro lens sheet, a lenticular lens sheet, and the like, and focus light to improve luminance.

Therefore, the backlight unit 200 including the light guide plate 120, the light sources 130a and 130b, and the first and second optical members 140 and 150 is configured.

The first liquid crystal panel 160 and the second liquid crystal panel 170 positioned on the first optical member 140 and the second optical member 150, respectively, are portions in which an image is realized, and the liquid crystal layer is interposed therebetween. The first substrate 161 and 171 and the second substrate 162 and 172 which are opposed to each other may be included.

Although not shown in the drawings, a plurality of pixels may be defined in the first substrates 161 and 171 called TFT array substrates by crossing a plurality of scan lines and data lines in a matrix shape. Each pixel may include a thin film transistor (TFT) capable of turning on / off a signal, and a pixel electrode connected to the thin film transistor may be positioned.

The second substrates 162 and 172, which are referred to as color filter substrates, include color filters of red (R), green (G), and blue (B) corresponding to a plurality of pixels, respectively, and surround the scan lines and the data lines. And a black matrix covering a non-display element such as a thin film transistor. In addition, a transparent common electrode covering them may be provided.

In addition, at least one side of the first and second liquid crystal panels 160 and 170 may be connected to the printed circuit board 163 through a connection member 164 or 174 such as a flexible circuit board or a tape carrier package (TCP). 173 may be connected and disposed in the upper panel guide 180a and the lower panel guide 180b during the modularization process.

When the thin film transistors selected for each scan line are turned on by the on / off signal of the gate driving circuit transmitted from the scan line, the first liquid crystal panel 160 and the second liquid crystal panel 170 having the above structure are turned on. The data voltage of the data driver circuit is transferred to the corresponding pixel electrode through the data line. Accordingly, the arrangement direction of the liquid crystal molecules may be changed by the electric field between the pixel electrode and the common electrode, thereby indicating a difference in transmittance.

The upper panel guide 180a and the lower panel guide 180b respectively fix the first optical member 140, the first liquid crystal panel 160, the second optical member 150, and the second liquid crystal panel 170. It serves to accommodate and support the light guide plate 120 and the light source 130.

Accordingly, the liquid crystal display device 100 of the present invention may be configured to accommodate the backlight unit 200, the first liquid crystal panel 160, and the second liquid crystal panel 170.

Meanwhile, the light source 130 described above may be an LED assembly, and the LED assembly includes a plurality of LED elements 135 arranged on the LED PCB 131.

The LED PCB 131 may be disposed in parallel with the first liquid crystal panel 160 or the second liquid crystal panel 170. In addition, the LED PCB 131 is disposed between the upper panel guide 180a and the lower panel guide 180b and fixed by them.

As such, when the LED PCB 131 is disposed in parallel with the first liquid crystal panel 160 or the second liquid crystal panel 170, the surface area of the LED PCB 131 may be increased. That is, the surface area of the LED PCB 131 can be made larger than before. Accordingly, there is an advantage that it is easy to discharge the heat generated in the plurality of LED elements 135 arranged on the LED PCB 131 to the outside.

In addition, the plurality of LED elements 135 arranged on the LED PCB 131 may be formed in a side view type. Conventional liquid crystal displays have a top view type in which LED PCBs are arranged vertically so that LED devices provide light to the light guide plate.

On the other hand, since the LED PCB 131 of the present invention is disposed in parallel with the first liquid crystal panel 160 or the second liquid crystal panel 170, in order to provide light to the light guide plate 120, the LED elements 135 are sided. It consists of a view type.

As described above, the structure of the light source 130 of the present invention in more detail as follows.

4 is a cross-sectional view showing a light source of the present invention, Figure 5 is a plan view showing a light source of the present invention.

Referring to FIG. 4, the light source 130 of the present invention includes an LED PCB 131, a copper layer 133 formed on the LED PCB 131, and a plurality of LED elements arranged in contact with the copper layer 133. 135).

The copper layer 133 formed on the LED PCB 131 serves as a heat sink for dissipating heat at the same time as the wiring for applying power to the LED elements 135. In addition, the plurality of LED elements 135 arranged in contact with the copper layer 133 may have a side view type to provide light.

In more detail, referring to FIG. 5, a copper layer 133 is formed on the LED PCB 131. The copper layer 133 includes a heat dissipation unit A for dissipating heat emitted from the LED elements 135 and a wiring unit B for applying power to the LED elements 135.

The heat dissipation unit A is an area in direct contact with the LED elements 135, and the wiring part B is an area in which wirings are applied to be spaced apart from the LED elements 135 to apply power. Here, the wiring part B includes a first wiring 137 for applying a positive power to the LED elements 135 and a second wiring 138 for applying a negative power.

Accordingly, when positive power is applied to the LED elements 135 through the first wiring 137 and negative power is applied through the second wiring 138, the LED elements 135 emit light. do.

The light source 130 illustrated in FIG. 5 illustrates a light source 130 obtained by dividing a plurality of LED elements 135 into four groups, and four second wires 138 are illustrated in one first wire 137. It is. However, the present invention is not limited thereto and may be variously made.

Meanwhile, in FIG. 5, the heat radiating portion A of the copper layer 133 serves to dissipate heat emitted from the LED elements 135 to the outside while applying a positive power from the first wiring 137. In the conventional LED PCB, the surface area of the heat dissipation portion A of the copper layer 133 was small, but in the present invention, since the width of the LED PCB 131 is increased, the surface area of the heat dissipation portion A of the copper layer 133 is increased. This is formed very large.

That is, in the present invention, by disposing the LED PCB 131 in parallel with the first liquid crystal panel or the second liquid crystal panel, the surface area of the heat dissipation portion A of the copper layer 133 can be large. Accordingly, the heat emitted from the plurality of LED elements 135 arranged on the LED PCB 131 is conducted to the heat radiating portion A of the copper layer 133 in contact with the LED elements 135, In the heat radiating portion A of the copper layer 133, the conducted heat is released to the outside at a large surface area.

Accordingly, the width w of the LED PCB 131 of the present invention may be 11 to 15mm. Here, when the width (w) of the LED PCB 131 is 11mm or more, there is an advantage that can efficiently dissipate heat emitted from the LED elements 135, the width (w) of the LED PCB 131 is 15mm Hereinafter, there is an advantage that the outer area of the liquid crystal display device can be prevented from growing.

As described above, the liquid crystal display device according to an embodiment of the present invention by arranging the LED PCB constituting the light source in parallel with the liquid crystal panels, and by forming the LED elements arranged in the LED PCB in a side view type, LED elements There is an advantage that can efficiently release the heat generated from the.

Table 1 shows the results of measuring the temperature for each part by driving the light source of the conventional liquid crystal display device and the light source of the liquid crystal display device of the present invention.

Conventional LCD Liquid crystal display device of the present invention Width of LED PCB 7 mm 11 mm 15 mm Temperature of wiring part (℃) 70.4 67.3 63.3 LED PCB Over Temperature (℃) 66.7 64.6 60.7 LED PCB Back Temperature (℃) 58.4 57.1 55.5

Referring to Table 1, it can be seen that the temperature of the liquid crystal display device light source of the present invention is significantly lower than the temperature of each part of the light source of the conventional liquid crystal display device.

Here, in the conventional LCD, since the LED PCB is disposed perpendicular to the liquid crystal panel as shown in FIG. 1, the width of the LED PCB is reduced to 7 mm or less. However, in the liquid crystal display device of the present invention, since the LED PCB is arranged horizontally on the liquid crystal panel, the width of the LED PCB may be increased to 11 to 15 mm, and thus the heat dissipation effect may be excellent.

As described above, the liquid crystal display device according to an embodiment of the present invention by arranging the LED PCB constituting the light source in parallel with the liquid crystal panels, and by forming the LED elements arranged in the LED PCB in a side view type, LED elements There is an advantage that can efficiently release the heat generated from the.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

Claims (6)

A light guide plate for guiding light;
A light source providing light to the light guide plate;
A first optical member on the light guide plate;
A first liquid crystal panel positioned on the first optical member;
A second optical member positioned below the light guide plate; And
A second liquid crystal panel disposed under the second optical member;
The light source includes an LED element and an LED PCB on which the LED element is arranged;
The LED PCB is a liquid crystal display device disposed in parallel with the first liquid crystal panel.
The method of claim 1,
The LED element is a side view type (LCD) device.
The method of claim 1,
And a lower panel guide for fixing the first optical member and the first liquid crystal panel, and a lower panel guide for fixing the second optical member and the second liquid crystal panel.
The method of claim 3, wherein
And the LED PCB is fixed between the upper panel guide and the lower panel guide.
The method of claim 1,
The light source includes a liquid crystal display device including the LED PCB, a copper layer positioned on the LED PCB, and LED elements arranged on the copper layer.
The method of claim 1,
The width of the LED PCB is 11 to 15mm liquid crystal display device.

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