KR20080058880A - Liquid crystal display - Google Patents

Abstract

An LCD(Liquid Crystal Display) is provided to mount an LED(Light Emitting Diode) driving chip on an additional PCB(Printed Circuit Board) and attach the PCB to a gate tape carrier package to prevent picture quality from deteriorating caused by interference between the LED driving chip and thin film transistors. An LCD(100) includes an LCD panel assembly(120) and an LED assembly(210). The LCD panel assembly includes an LCD panel(126), a first PCB(135), a second PCB(137) and a tape carrier package(132). The first PCB is electrically connected to one side of the LCD panel, generates a plurality of driving signals and provides the driving signals to the LCD panel. The tape carrier package is electrically connected to the other side of the LCD panel and has a first driving chip mounted thereon. The second PCB is attached to the tape carrier package and has a second driving chip mounted thereon. The LED assembly provides light to the LCD panel and includes a plurality of LED elements.

Description

Liquid crystal display

1 is an exploded perspective view illustrating a liquid crystal display according to a first embodiment of the present invention.

2 is a partially enlarged perspective view illustrating an enlarged portion A of FIG. 1.

3 is a perspective view illustrating a coupling relationship between a second printed circuit board, an LED assembly, and a flexible printed circuit board according to a first embodiment of the present invention.

4 is an exploded perspective view illustrating a liquid crystal display according to a second exemplary embodiment of the present invention.

5 is a partially enlarged perspective view illustrating an enlarged portion A of FIG. 4.

6 is a perspective view illustrating a coupling relationship between a liquid crystal panel and an LED assembly according to a second exemplary embodiment of the present invention, and a flexible printed circuit board.

(Explanation of symbols for the main parts of the drawing)

100: liquid crystal display 110: top chassis

120: liquid crystal panel assembly 123: common electrode display panel

124: thin film transistor array panel 126: liquid crystal panel

132: gate tape carrier package 134: data tape carrier package

135: first printed circuit board 136: LED driving chip

137: second printed circuit board 140: backlight assembly

141: optical sheets 142: light guide plate

160: bottom chassis 170: bottom chassis

210: LED assembly 300: flexible cable

400, 500: connector 600: flexible printed circuit board

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of minimizing defects.

In the liquid crystal display device (hereinafter referred to as LCD), a liquid crystal layer is interposed between a color filter display panel on which a reference electrode and a color filter are formed, and a thin film transistor substrate on which a thin film transistor and a pixel electrode are formed. By applying different potentials to the pixel electrode and the reference electrode, an electric field is formed to change the arrangement of the liquid crystal molecules, and thereby, the image is represented by adjusting the light transmittance.

Since the liquid crystal molecules display an image by changing the transmittance of light by the direction and intensity of the electric field, the liquid crystal display requires light for displaying an image. Light sources used in liquid crystal displays include light emitting diodes (hereinafter referred to as LEDs), cold cathode fluorescent lamps (hereinafter referred to as CCFLs), and flat fluorescent lamps (FFLs). ) Is representative.

Conventionally, many CCFLs are mainly used in liquid crystal displays, but in recent years, many FFLs or LEDs have been used. Among these, in recent years, the LED which has small power consumption and high brightness is used.

The LED driving chip that provides the driving voltage for driving the LED may be mounted on an integrated printed circuit board or on a separate printed circuit board. Here, when the LED driving chip is mounted on the integrated printed circuit board, there is an advantage that a separate printed circuit board is not required, but defects such as image quality abnormality may occur due to interference with the thin film transistor formed in the liquid crystal panel. In addition, when the LED driving chip is mounted on a separate printed circuit board, a separate printed circuit board may be located at the lower end of the liquid crystal panel, thereby limiting space utilization. In addition, a separate printed circuit board is connected to the integrated printed circuit board by the flexible printed circuit board, where the flexible printed circuit board may be bent or disconnected.

An object of the present invention is to provide a liquid crystal display device capable of minimizing defects.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, a liquid crystal display device includes: a liquid crystal panel displaying an image; and electrically connected to one side of the liquid crystal panel and generating a plurality of driving signals to provide the liquid crystal panel. A first printed circuit board, a tape carrier package electrically connected to the other side of the liquid crystal panel, and a second printed circuit board attached to the tape carrier package and mounted on the tape carrier package. To provide a liquid crystal panel assembly and light to the liquid crystal panel, and includes an LED assembly comprising a plurality of LED elements.

In accordance with another aspect of the present invention, a liquid crystal display device includes: a liquid crystal panel for displaying an image; and an LCD connected to one side of the liquid crystal panel and generating a plurality of driving signals to provide the liquid crystal panel. A first printed circuit board, a liquid crystal panel assembly including a tape carrier package electrically connected to the other side of the liquid crystal panel and mounted with first and second driving chips, and providing light to the liquid crystal panel, wherein the liquid crystal panel And an LED assembly electrically connected to and including a plurality of LED elements.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, a liquid crystal display according to an exemplary embodiment will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view illustrating a liquid crystal display according to a first embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display 100 according to the first exemplary embodiment of the present invention generally includes a liquid crystal panel assembly 120, a backlight assembly 140, a top chassis 110, and a bottom chassis 160. do.

The liquid crystal panel assembly 120 includes a thin film transistor array panel 124, a liquid crystal panel 126 including a common electrode display panel 123, a liquid crystal (not shown), a gate tape carrier package 132, and a data tape carrier package ( 134 and the first printed circuit board 135.

The liquid crystal panel 126 includes a thin film transistor array panel 124 including a gate line (not shown) and a data line (not shown), a thin film transistor array, a pixel electrode, and the like, a black matrix, a common electrode, and the like. And a common electrode display panel 123 disposed to face the thin film transistor array panel 124. The liquid crystal panel 126 serves to display image information.

The gate tape carrier package 132 is connected to each gate line (not shown) formed on the thin film transistor array panel 124, and the data tape carrier package 134 is connected to each data line (not shown) formed on the thin film transistor array panel 124. Is connected).

Meanwhile, in the first printed circuit board 135, various driving components for processing the gate driving signal input to the gate tape carrier package 132 and the data driving signal input to the data tape carrier package 134 are mounted. In other words, the first printed circuit board 135 is connected to the liquid crystal panel 126 to provide image information.

In addition, the backlight assembly 140 may include the optical sheets 141, the light guide plate 142, the LED assembly 210, the reflector plate 146, and the like.

Here, the light guide plate 142 serves to guide the light supplied to the liquid crystal panel assembly 120. The light guide plate 142 is formed of a panel of a plastic-based transparent material such as acryl to propagate light generated from the LED assembly 210 toward the liquid crystal panel 126 seated on the light guide plate 142. Therefore, various patterns may be formed on the rear surface of the light guide plate 142 to convert the traveling direction of light incident into the light guide plate 142 toward the liquid crystal panel 126. In this arrangement structure, the light guide plate 142 is preferably formed in a flat type with a substantially uniform thickness so that light is uniformly transmitted to the entire display screen. However, the present invention is not limited thereto, and light guide plates having various shapes may be applied.

The LED assembly 210 is disposed on one side of the light guide plate 142. The LED assembly 210 is disposed on a sidewall of the light guide plate 142 facing the first printed circuit board 135. In this case, the LED assembly 210 is formed at the ends of the flexible printed circuit board 212, the plurality of LED elements 214 connected to the flexible printed circuit board 212, and the flexible printed circuit board 212. 2 includes a connector 216 for connecting to the printed circuit board 137. In this case, the LED device 214 includes R, G, and B LED devices. In order to implement a liquid crystal display having a constant brightness, the LED elements 214 are preferably arranged at regular intervals.

In addition, the LED assembly 210 is electrically connected to a second printed circuit board 137 on which an inverter (not shown) and an LED driving chip (not shown) are mounted by a flexible printed circuit board (not shown). The second printed circuit board 137 is attached to the gate tape carrier package 132.

Here, the second printed circuit board 137 is electrically connected to the first printed circuit board 135 by the connector 300, and receives a signal for driving the inverter from the first printed circuit board 135. A driving voltage is generated and provided to the LED element 214.

The reflective plate 146 is installed on the lower surface of the light guide plate 142 to reflect the light emitted to the bottom of the light guide plate 142 to the top. The reflecting plate 146 reflects the light not reflected by the fine pattern on the rear surface of the light guide plate 142 back toward the exit surface of the light guide plate 142, thereby reducing the light loss of the light incident on the liquid crystal panel 126 and at the same time the light guide plate 142. It serves to improve the uniformity of the light transmitted to the exit surface of the).

The optical sheets 141 are installed on the upper surface of the light guide plate 142 to diffuse and collect light transmitted from the light guide plate 142. The optical sheets 141 include a diffusion sheet, a prism sheet, a protective sheet, and the like. The diffusion sheet positioned between the light guide plate 142 and the prism sheet disperses the light incident from the light guide plate 142 to prevent the light from being partially concentrated. The prism sheet has a triangular prism with a regular arrangement on the upper surface, and is usually composed of two sheets, and each prism array is arranged so as to cross each other at a predetermined angle, so that the light diffused from the diffusion sheet is a liquid crystal panel. Condensing in a direction perpendicular to the (126). As a result, the light passing through the prism sheet almost runs vertically so that the luminance distribution on the protective sheet is uniformly obtained. The protective sheet formed on the prism sheet not only serves to protect the surface of the prism sheet, but also serves to diffuse light in order to make the distribution of light uniform. The configuration of the optical sheets 141 is not limited to the above example, and may be variously changed according to the specifications of the liquid crystal display device 100.

The liquid crystal panel assembly 120 is installed on the protective sheet and is seated in the bottom chassis 160 together with the backlight assembly 140. The bottom chassis 160 has sidewalls formed along edges of the bottom surface to receive and fix the backlight assembly 140 and the liquid crystal panel assembly 120 in the sidewalls, and the backlight assembly 140 includes a plurality of sheets. To prevent bending. The first printed circuit board 135 of the liquid crystal panel assembly 120 is bent along the outer surface of the bottom chassis 160 to be seated on the rear surface of the bottom chassis 160. Here, the shape of the bottom chassis 160 may be variously modified according to a method of accommodating the backlight assembly 140 or the liquid crystal panel assembly 120 in the bottom chassis 160.

The top chassis 110 is disposed to be coupled to the bottom chassis 160 to cover the top surface of the liquid crystal panel assembly 120 of the bottom chassis 160. A window for exposing the liquid crystal panel assembly 120 to the outside is formed on an upper surface of the top chassis 110.

The top chassis 110 may be coupled to the bottom chassis 160 through hooks (not shown). For example, hooks may be formed along the outer surface of the side wall of the bottom chassis 160, and the hooks and corresponding hooks may be inserted. A ball (not shown) may be formed on the side of the top chassis 110. Accordingly, as the top chassis 110 descends from the top of the bottom chassis 160, the hooks formed in the bottom chassis 160 enter the hook insertion holes of the top chassis 110, and thus the bottom chassis 160 and the top chassis 110. ) Can be fastened. In addition, the combination of the top chassis 110 and the bottom chassis 160 may be modified in various forms.

2 is a partially enlarged perspective view illustrating an enlarged portion A of FIG. 1.

2, there is shown a connector coupling assembly between the first and second printed circuit boards 135 and 137 and the flexible cable 300 according to the first embodiment of the present invention. Connectors 400 and 500 for flexible cables include housings 410 and 510 made of an insulator, a plurality of lead wires 430 and 530 formed on one side of the housings 410 and 510, and housings 410 and 510. It is formed on the other side of the flexible cable (400, 300) includes a slot (slot) 414 for coupling with the cable holder 302.

On one side of the housing 410, 510, a plurality of lead wires 430, 530 extending to a predetermined length are densely arranged. Each of the plurality of lead wires 430 and 530 is electrically connected to the circuit patterns formed on the fixed first and second printed circuit boards 135 and 137 by soldering.

In addition, a slot 414 into which the cable holder 302 of the flexible cable 200 is inserted is formed at the other side of the housings 410 and 510. Here, a plurality of connection pins 440 are arranged in the slot 414. The plurality of lead wires 430 and 530 and the plurality of connection pins 440 are connected to each other corresponding to each other.

The flexible cable 300 is composed of a cable holder 302 made of an insulator and a plurality of conductive wires 304 insulated from and separated from each other. A plurality of connection terminals 306 are arranged inside the cable holder 302, and the cable holder 302 is inserted into the slots 414 of the connectors 400 and 500 to be electrically connected to the plurality of connection pins 440. Connected. The plurality of conductive wires 304 serves to provide an inverter driving signal generated by the first printed circuit board 135 to the second printed circuit board 137 through the flexible cable 300. Here, the plurality of conductive wires 304 constituting the cable holder 302 are connected to the connection pins 440 of the connector 300 and ones corresponding to each other. The flexible cable connectors 400 and 500 and the cable holder 302 may be hooked in a state where they are fastened to each other.

3 is a perspective view illustrating a coupling relationship between a second printed circuit board, an LED assembly, and a flexible printed circuit board according to a first embodiment of the present invention.

Referring to FIG. 3, the coupling of the second printed circuit board 137 and the LED assembly 210 uses a flexible printed circuit board 600. That is, the connection pad 620 formed on the flexible printed circuit board 600 is connected to the connectors 700 and 800 mounted on the LED assembly 210 and the second printed circuit board 137, and the second printed circuit board ( The LED driving voltage generated at 137 is transferred to the LED assembly 210 through the flexible printed circuit board 600.

Here, the flexible printed circuit board 600 is formed by forming a conductor pattern on one surface of a film having flexibility and insulation, for example, a base film 601 having a polyimide material, and capable of transmitting an electrical signal. The structure includes a wiring pattern 610 constituting a predetermined circuit with a plurality of signal lines and a connection pad 620 formed at one end of the base film 601.

The wiring pattern 610 is formed to a thickness of about 5 to 20 μm, and a metal material such as copper foil (Cu) is generally used. Preferably, the surface of the copper foil is plated with tin, gold, nickel or solder. Conduct.

A method of forming copper foil, which is an example of such a wiring pattern 410, includes casting, laminating, electroplating, and the like. Here, casting is a method of thermal curing by spraying a liquid base film on a rolled copper foil, laminating is a method of placing a rolled copper foil on a base film and thermocompression bonding. In addition, electroplating is a method of forming a copper foil by depositing a copper seed layer on the base film and then putting the base film into an electrolyte in which copper is melted and flowing electricity. Here, the wiring patterned on the copper foil is formed to constitute a predetermined circuit by performing a photo / etching process on the copper foil and selectively etching the copper foil.

An insulating protective film (not shown) is formed on the wiring pattern 610 so as to protect the wiring pattern 610 from external impact or corrosion. As the insulating protective film, a solder resist may be representatively used.

The connection pad 620 formed at one end of the base film 401 is a part for electrical connection with the outside. The connection pad 620 may be formed of a conductive material, for example, the same material as the wiring pattern 410. The connection pad 620 of the flexible printed circuit board 600 may be formed at the other end opposite to one end of the base film 601.

The connectors 700 and 800 include body parts 701 and 801 and contact terminals 811 that are coupled to the connection pads 620 of the flexible printed circuit board 600. In addition, the connectors 700 and 800 may include a cover part (not shown) covering the contact terminals 811.

That is, the connectors 700 and 800 are contact parts including a plurality of contact terminals 811 coupled to the connection pads 620 of the flexible printed circuit board 600 on the body parts 701 and 801 formed of synthetic resin. Comprising a structure including a 820, and is mounted on the second printed circuit board 137 and the LED assembly 210, respectively.

Here, the contact terminals 811 of the contact portion 820 formed on the second printed circuit board 137 correspond to the connection pads 620 of the flexible printed circuit board 600. Similarly, contact terminals (not shown) of contacts (not shown) formed on the LED assembly 210 correspond to connection pads (not shown) of the flexible printed circuit board 600. The contact terminals of these contacts are made of a conductive material, and are preferably arranged at uniform separation distances.

4 is an exploded perspective view illustrating a liquid crystal display according to a second exemplary embodiment of the present invention.

In the second embodiment of the present invention, the LED driving chip (not shown) is mounted on the gate tape carrier package 132 together with the gate driving chip (not shown), and the liquid crystal panel 126 and the LED assembly 210 are flexible. Except that connected by the printed circuit board 600 is the same as the first embodiment (see Fig. 1) of the present invention, the rest of the description will be omitted for convenience of description.

Referring to FIG. 4, an LED driving chip (not shown) is mounted on a gate tape carrier package 132 connected to the liquid crystal panel 126 along with a gate driving chip (not shown). In this case, according to the method of mounting the driving chip on the gate tape carrier package 132, it may be mounted in a chip on glass (COG), a chip on film (COF) method. In the chip on glass method, an anisotropic conductive film is used in a gate region of a liquid crystal panel to mount a driving chip in the form of a semiconductor package. In the chip-on-film method, the driving chip is mounted on a flexible printed circuit board having high bending flexibility, and the chip is mounted on the flexible printed circuit board using a tab automated bonding (TAB) mounting method.

Here, an inverter (not shown) is mounted on the first printed circuit board 135, and the LED driving chip is a driving signal output from the inverter through a gate transmission line (not shown) formed on the liquid crystal panel 126. The LED driving voltage is generated to provide the LED driving voltage to the LED device 214.

In addition, the liquid crystal panel 126 and the LED assembly 210 are electrically connected by a flexible printed circuit board (not shown). Here, the liquid crystal panel 126 has a connection terminal (not shown) for transmission wiring, one side of the flexible printed circuit board is connected with the connection terminal for transmission wiring, and the other side is a connector (not shown) formed in the LED assembly 210. Is connected to The LED driving voltage generated in the LED driving chip of the gate tape carrier package 132 is transferred to the LED assembly 210 through the flexible printed circuit board.

5 is a partially enlarged perspective view illustrating an enlarged portion A of FIG. 4.

Referring to FIG. 5, the resin film 118 is attached to the gate line connection terminal 114 formed on the liquid crystal panel 126, the gate tape carrier package 132 is aligned, and then the gate tape carrier package 132 is provided. ) Is attached to the liquid crystal panel using heat and pressure. At this time, regions other than the lead of the gate tape carrier package 132 are bonded by the resin film 118. Here, reference numeral 112 denotes a gate line.

The gate driving signal generated by the first printed circuit board 135 is transmitted to the liquid crystal panel 126 through the wiring of the gate tape carrier package 132, and at this time, the LED driving generated by the first printed circuit board 135 is driven. The signal is transmitted to the LED driving chip 136 through the wiring formed in the gate tape carrier package 132. The LED driving chip 136 receives the LED driving signal to generate the LED driving voltage, and transmits the LED driving voltage to the LED assembly 210 through the connection terminal 116 for the transmission wiring.

6 is a perspective view illustrating a coupling relationship between a liquid crystal panel and an LED assembly according to a second exemplary embodiment of the present invention, and a flexible printed circuit board.

Referring to FIG. 6, the coupling between the liquid crystal panel 126 and the LED assembly 210 uses a flexible printed circuit board 600. That is, the connection pad 620 formed on the flexible printed circuit board 600 is connected to the connector 700 on the connection terminal 116 for transmission wiring formed on the liquid crystal panel 126 and the 216 mounted on the LED assembly 210. The LED driving voltage generated by the LED driving chip 136 of the gate tape carrier package 132 is transferred to the LED assembly 210 through the connection terminal 116 for the transmission wiring.

The connector 700 includes a body portion 701 and a contact terminal (not shown) coupled to the connection pad 620 of the flexible printed circuit board 600. In addition, the connector 700 may include a cover part that covers the contact terminals.

That is, the structure includes a contact portion (not shown) having a plurality of contact terminals coupled to the connection pad 620 of the flexible printed circuit board 600 in the body portion 701 of the connector 700, LED It is mounted and positioned on the assembly 210.

Here, the connection terminal 116 for transmission wiring formed on the liquid crystal panel 126 is correspondingly coupled to the connection pads 620 of the flexible printed circuit board 600. Similarly, the contact terminals of the contacts formed on the LED assembly 210 correspond to the connection pads 620 of the flexible printed circuit board 600. The contact terminals of these contacts are made of a conductive material, and are preferably arranged at uniform separation distances.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the liquid crystal display device according to the present invention, an LED driving chip is mounted on a separate printed circuit board, and a separate printed circuit board is attached to the gate tape carrier package to generate the interference due to interference with the thin film transistor. Defects such as abnormal image quality can be prevented.

In addition, the LED driving chip may be mounted on the gate tape carrier package, thereby reducing the space utilization and minimizing the bending or disconnection of the flexible printed circuit board.

Claims (16)

A liquid crystal panel for displaying an image, a first printed circuit board electrically connected to one side of the liquid crystal panel and generating a plurality of driving signals to the liquid crystal panel, and electrically connected to the other side of the liquid crystal panel; A liquid crystal panel assembly including a tape carrier package having a driving chip mounted thereon and a second printed circuit board attached to the tape carrier package and having a second driving chip mounted thereon; And And a LED assembly that provides light to the liquid crystal panel and includes a plurality of LED elements. The method of claim 1, And the LED assembly and the second printed circuit board are electrically connected to each other by a flexible printed circuit board. The method of claim 2, The LED assembly and the second printed circuit board each include a first connector and a second connector, one side of the flexible printed circuit board is connected to the first connector, the other side is connected to the second connector . The method of claim 2, The flexible printed circuit board transfers the LED driving voltage generated by the second printed circuit board to the LED assembly. The method of claim 1, And the first and second driving chips are gate driving chips and LED driving chips, respectively. The method of claim 1, And the first printed circuit board and the second printed circuit board are electrically connected by cables, and transmit a plurality of driving signals generated by the first printed circuit board to the second printed circuit board. The method of claim 1, And a tape carrier package disposed between the liquid crystal panel and the first printed circuit board and mounted with a third driving chip. The method of claim 7, wherein The third driving chip is a data driving chip. A liquid crystal panel for displaying an image, a first printed circuit board electrically connected to one side of the liquid crystal panel and generating a plurality of driving signals to the liquid crystal panel, and electrically connected to the other side of the liquid crystal panel; And a tape carrier package on which the second driving chip is mounted. And And a LED assembly providing light to the liquid crystal panel and electrically connected to the liquid crystal panel and including a plurality of LED elements. The method of claim 9, And the LED assembly and the liquid crystal panel are electrically connected to each other by a flexible printed circuit board. The method of claim 10, The LED assembly includes a connector, one side of the flexible printed circuit board is connected to the connector, the other side is connected to the connection terminal formed on the liquid crystal panel. The method of claim 10, The flexible printed circuit board transfers the LED driving voltage generated by the second printed circuit board to the LED assembly. The method of claim 9, And the first and second driving chips are gate driving chips and LED driving chips, respectively. The method of claim 9, The plurality of driving signals generated by the first printed circuit board are transferred to the tape carrier package through a transmission line formed on the liquid crystal panel. The method of claim 9, And a tape carrier package disposed between the liquid crystal panel and the first printed circuit board and mounted with a third driving chip. The method of claim 15, The third driving chip is a data driving chip.

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