KR20050077496A - Liquid crystal panel assembly and liquid crystal display device having the same - Google Patents

Abstract

 A liquid crystal panel assembly and a liquid crystal display device having the same are disclosed. The liquid crystal panel assembly includes a liquid crystal panel, a printed circuit board, and a flexible circuit board. The liquid crystal panel includes a thin film transistor substrate, a color filter substrate, and a liquid crystal layer. The thin film transistor substrate includes a ground pattern. The printed circuit board includes drive elements and ground wiring. The flexible circuit board electrically connects the ground pattern and the ground wiring to provide a ground path for electromagnetic waves flowing from the outside. Therefore, the reliability of the liquid crystal panel assembly against electromagnetic interference interference is improved, and the image quality of the liquid crystal display device is improved.

Description

Liquid crystal panel assembly and liquid crystal display device having the same {LIQUID CRYSTAL PANEL ASSEMBLY AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

The present invention relates to a liquid crystal panel assembly and a liquid crystal display device having the same. More particularly, the present invention relates to a liquid crystal panel assembly and a liquid crystal display device having the same prevented from interference by electromagnetic waves introduced from the outside.

Recently, the liquid crystal display device (LCD), which has been spotlighted as a substitute for cathode ray tube (CRT) due to its small size, light weight, and low power consumption, is a display device using the electro-optic properties of the liquid crystal injected into the liquid crystal panel.

Generally used transmissive liquid crystal display devices are light-receiving elements that do not emit light of their own, so a backlight assembly for generating light and transmitting light toward the liquid crystal panel is required. It depends not only on the liquid crystal display itself but also on the performance of the backlight assembly.

Recently, as the liquid crystal display device is thin and short, the components included in the backlight assembly, for example, a lamp unit, a light guide plate, a printed circuit board, and the like, have become smaller, thinner, and lighter.

In addition, the effective area of the screen of the liquid crystal panel is increased so that the liquid crystal display has a high quality and a large screen. Accordingly, the lamp unit and the liquid crystal panel are partially overlaid and the separation distance between the two is gradually reduced.

As a result, the high frequency signal for driving the lamp unit causes mutual interference with the high frequency signal applied to the liquid crystal panel at an undesired frequency, thereby degrading the image quality of the liquid crystal display device.

The object of the present invention is devised in view of the above problems,

Disclosure of Invention An object of the present invention is to provide a liquid crystal panel assembly having improved reliability for preventing electromagnetic interference by arranging a ground pattern or a ground wire on a substrate to induce and ground electromagnetic waves introduced from the outside.

Another object of the present invention is to provide a liquid crystal display device including the liquid crystal panel assembly as described above, in which image degradation is prevented due to the inflow of electromagnetic waves from the outside.

In order to realize the above object of the present invention, the liquid crystal panel assembly according to an embodiment of the present invention includes a liquid crystal panel, a printed circuit board and a flexible circuit board. The liquid crystal panel includes a thin film transistor substrate, a color filter substrate, and a liquid crystal layer. The thin film transistor substrate includes a ground pattern. The ground pattern induces electromagnetic waves transmitted from the outside to the outside of the liquid crystal panel and grounds them. The color filter substrate is disposed to face the thin film transistor substrate and includes color pixels of red, green, and blue. The liquid crystal layer is disposed between the thin film transistor substrate and the color filter substrate. The liquid crystal layer emits light by changing an optical characteristic of incident light according to an electric field formed between the thin film transistor substrate and the color filter substrate. The printed circuit board includes driving elements and a ground wiring. The driving elements generate a panel driving signal for driving the liquid crystal panel. The ground wiring grounds the electromagnetic waves emitted from the driving elements. The flexible circuit board electrically connects the ground pattern and the ground wiring to each other to provide a ground path of electromagnetic waves flowing from the outside.

Optionally, the color filter substrate further includes an auxiliary ground pattern. The auxiliary ground pattern is electrically interconnected with the ground pattern. Preferably, the ground pattern and the assistant ground pattern are disposed outside the region corresponding to the liquid crystal layer among the thin film transistor substrate and the color filter substrate, respectively.

In order to realize another object of the present invention, a liquid crystal display according to an embodiment of the present invention includes a mold frame, a backlight assembly, a liquid crystal panel, a printed circuit board, a flexible circuit board and a top chassis. The mold frame includes a receiving portion. The backlight assembly includes a lamp unit, a reflecting plate, a light guide plate, and an optical sheet. The lamp unit is disposed on a side surface of the accommodating part, and the reflecting plate, the light guide plate, and the optical sheet are sequentially stored on the base surface of the accommodating part. The liquid crystal panel includes a thin film transistor substrate, a color filter substrate, and a liquid crystal layer. In order to block interference by electromagnetic waves emitted from the lamp unit, the thin film transistor substrate includes a ground pattern. The ground pattern is disposed in a region of the thin film transistor substrate corresponding to the lamp unit. The color filter substrate is disposed to face the thin film transistor substrate and includes color pixels of red, green, and blue. The liquid crystal layer is disposed between the thin film transistor substrate and the color filter substrate. The printed circuit board includes driving elements for generating a panel driving signal applied to the liquid crystal panel and a ground wiring for grounding electromagnetic waves emitted from the driving element. The flexible circuit board electrically connects the ground pattern and the ground wiring to each other to provide a ground path of electromagnetic waves flowing from the lamp unit. The top chassis covers the edge of the liquid crystal panel and is fastened to the mold frame.

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

LCD panel assembly

1 is a perspective view of a liquid crystal panel assembly according to an embodiment of the present invention.

Referring to FIG. 1, the liquid crystal panel assembly includes a liquid crystal panel 130, a printed circuit board, and a flexible circuit board. The liquid crystal panel 130 includes a thin film transistor substrate 131, a color filter substrate 135, and a liquid crystal layer.

The thin film transistor substrate 131 includes a ground pattern 134. The ground pattern 134 induces electromagnetic waves transmitted from the outside to the outside of the liquid crystal panel 130 to ground them.

Specifically, the thin film transistor substrate 131 further includes a transparent substrate, source lines 133, gate lines 132, pixel electrodes, and switching elements. In FIG. 1, the pixel electrodes and the switching elements are not illustrated for the sake of schematic description, and only a portion of the transparent substrate, the source lines 133, and the gate lines 132 are illustrated. Gate input pads 132 ′ are disposed at ends of the gate lines 132. A selection signal is applied from the outside to the gate input pads 132 ′ of the gate lines 132.

Source input pads 133 ′ are disposed at ends of the source lines 133. The source lines 133 are insulated from the gate lines 132, and a data signal including image information is applied to the source input pad 133 ′ from the outside. Accordingly, a plurality of pixel regions surrounded by the adjacent gate lines 132 and the adjacent source lines 133 are formed in the transparent substrate.

The pixel electrodes are disposed in the pixel areas. The pixel electrodes are electrodes on one side of the capacitor and are made of a transparent conductive material. The switching elements are disposed in a boundary region of the pixel regions. The switching element includes electrodes electrically connected to the gate line 132, the source line 133, and the pixel electrode, respectively. The switching element applies the data signal applied from the source line 133 to the pixel electrode according to the selection signal applied from the gate line 132.

The ground pattern 134 is disposed in parallel with the gate lines 132 at the long side edge of the transparent substrate. The ground pattern 134 may include metal wires made of a metal material.

The color filter substrate 135 is disposed to face the thin film transistor substrate 131. The color filter substrate 135 includes a glass substrate, a color pixel, and a common electrode. The color pixels include red, green, and blue color pixels, and are disposed on the glass substrate corresponding to the pixel area. The common electrode is disposed in the entire area of the glass substrate on which the color pixels are disposed. In order to form a cell gap for disposing the liquid crystal layer, which will be described later, a distance between the thin film transistor substrate 131 and the color filter substrate 135 is maintained at about several tens of micrometers (μm). In another embodiment, the color filter substrate 135 may further include an auxiliary ground pattern to improve the electromagnetic wave grounding efficiency.

The liquid crystal layer is disposed between the thin film transistor substrate 131 and the color filter substrate 135 and sealed by a sealant. The liquid crystal molecules in the liquid crystal layer are arranged to have a specific orientation. The ground pattern 134 is disposed outside the region of the thin film transistor substrate 131 corresponding to the liquid crystal layer.

Meanwhile, one end of the other long side and the short side facing the long side of the thin film transistor substrate 131 is exposed to the outside of the color filter substrate 135. The gate input pad 132 ′ is disposed near the other long side of the thin film transistor substrate 131 exposed to the outside of the color filter substrate 135, and the source input pad 133 ′ is disposed on the color filter substrate ( It is disposed near the short side of the thin film transistor substrate 131 exposed to the outside of the 135. In addition, the gate lines 132 and the source lines 133 are disposed in a region of the thin film transistor substrate 131 corresponding to the liquid crystal layer.

An area where the gate input pad 132 ′ is exposed is defined as a gate region 137, and an area where the source input pad 133 ′ is exposed is defined as a source region 138. The ground pattern 134 is disposed at the same length as the gate line 132 near the long side of the thin film transistor substrate 131 facing the source region 138.

When the data signal is applied to the pixel electrode, an electric field is formed between the pixel electrode and the common electrode. Accordingly, the arrangement of the liquid crystal molecules is changed, and an optical property of light passing through the liquid crystal layer, for example, transmittance is changed to display an image on the liquid crystal panel 130.

The printed circuit board includes a gate printed circuit board 160 and a source printed circuit board. The gate printed circuit board 160 is electrically connected to the gate region 137 by a gate flexible circuit board 170 to be described later. The source printed circuit board is electrically connected to the source region 138 by a source flexible circuit board.

For simplicity, FIG. 1 illustrates only the gate printed circuit board 160 and the gate flexible circuit board 170. Hereinafter, the gate printed circuit board 160 and the gate flexible circuit board 170 will be described as an example. The gate printed circuit board 160 includes driving elements and a ground wiring 164.

The driving elements generate a panel driving signal for driving the liquid crystal panel 130. The gate printed circuit board 160 further includes an output pad 162. The output pad 162 is disposed at one end of the gate printed circuit board 160 facing the liquid crystal panel 130. The ground wiring 164 is disposed at an edge of the gate printed circuit board 160 and guides and grounds electromagnetic waves generated from the driving elements to the outside of the gate printed circuit board 160.

The gate flexible circuit board 170 includes a base film 171, a driving drive integrated circuit (IC) 172, and a metal wiring 175.

 The drive drive IC 172 is mounted on one surface of the base film 171. The driving drive IC 172 controls the panel driving signal generated by the driving device to generate the selection signal. The metal wire 175 is printed on the base film 171. The metal wire 175 includes an input wire 176, an output wire 174, and a dummy wire 178.

The input wiring 176 is disposed at a portion of the base film 171 facing the gate printed circuit board 160 with respect to the driving drive IC 172. The conductive lines forming the input wiring 176 are arranged such that the intervals therebetween have a first pitch. The input wiring 176 is electrically connected to the output pad 162 of the gate printed circuit board 160 to apply the panel driving signal generated from the driving elements to the driving drive IC 172. .

The output wiring 174 is disposed in a portion of the base film 171 facing the liquid crystal panel 130 with respect to the driving drive IC 172. The conductive lines forming the output line 174 are arranged to have a second pitch smaller than the first pitch. The output line 174 is electrically connected to the gate gate input pad 132 ′ disposed on the thin film transistor substrate 131 to apply the selection signal.

The dummy wiring 178 is patterned in a direction from the gate printed circuit board 160 toward the liquid crystal panel 130 at both ends of the base film 171. One end of the dummy wiring 178 in the direction in which the output wiring 174 is formed is electrically connected to the ground pattern 134 disposed on the thin film transistor substrate 131 and faces the one end of the dummy wiring. The tartan portion 178 is electrically connected to the ground wiring 164 of the gate printed circuit board 160. Accordingly, the dummy wiring 178 electrically connects the ground pattern 134 and the ground wiring 164 to each other, thereby providing a ground path of electromagnetic waves introduced from the outside and electromagnetic waves emitted from the driving elements.

LCD Display

2 is a partial cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the liquid crystal display device 100 includes a mold frame 110, a backlight assembly 120, a liquid crystal panel 130, a printed circuit board, a flexible circuit board, and a top chassis 150.

The mold frame 110 includes a receiving unit. In FIG. 2, the mold frame 110 includes a bottom portion and sidewalls defining the accommodating portion.

The backlight assembly 120 includes a lamp unit 122, a reflecting plate 124, a light guide plate 126, and an optical sheet 128.

The lamp unit 122 is disposed on the side surface of the accommodating part, that is, the side wall. Preferably, the lamp unit 122 is disposed near the side wall extending from the long side of the base surface of the housing.

The lamp unit 122 includes a lamp and a lamp reflector. The lamp is, for example, a fluorescent lamp, and the lamp reflector surrounds the lamp and reflects light emitted from the lamp toward one side of the light guide plate 126 which will be described later. The reflective plate 124, the light guide plate 126, and the optical sheets 128 are sequentially disposed on the base surface of the housing. The light guide plate 126 guides the light provided from the lamp unit 122 and emits the light to the upper portion of the accommodating part. The reflective plate 124 is disposed between the base surface of the accommodating portion and the light guide plate 126 to re-inject light leaked from the light guide plate 126 into the light guide plate 126 to improve light utilization efficiency. The optical sheets 128 are disposed on the light guide plate 126 to improve optical characteristics of light emitted from the light guide plate 126.

The liquid crystal panel 130 is substantially the same as the liquid crystal panel 130 illustrated in FIG. 1 except that the color filter substrate 135 further includes an auxiliary ground pattern 139. The same reference numerals will be given, and redundant description thereof will be omitted.

The liquid crystal panel 130 is disposed on the backlight assembly 120. The liquid crystal panel 130 displays an image through light provided from the backlight assembly 120 and panel driving signals provided from the gate printed circuit board 160 and the source printed circuit board. In the liquid crystal panel 130, the source region 138 and the ground pattern 134 are disposed to face each other, and the liquid crystal panel 130 has the ground pattern 134 connected to the lamp unit 122. It is arranged to correspond.

In order to improve the grounding efficiency of the electromagnetic wave emitted from the lamp unit 122, the color filter substrate 135 further includes an auxiliary grounding pattern 139. The auxiliary ground pattern 139 is disposed in a region of the color filter substrate 135 corresponding to the ground pattern 134 of the thin film transistor substrate 131.

The auxiliary ground pattern 139 is electrically connected to the ground pattern 134. Since the ground pattern 134 and the auxiliary ground pattern 139 are disposed in close proximity to each other, for example, when the laser is irradiated to the thin film transistor substrate 131 or the color filter substrate 135, a metal material is formed. The ground pattern 134 and the auxiliary ground pattern 139 are connected to each other while melting in a column.

In FIG. 2, the ground pattern 134 and the assistant ground pattern 134 are respectively disposed outside the region corresponding to the liquid crystal layer 136 of the thin film transistor substrate 131 and the color filter substrate 135. Is placed.

Since the printed circuit board and the flexible circuit board are substantially the same as the printed circuit board and the flexible circuit board described with reference to FIG. 1, redundant description thereof will be omitted.

The top chassis 150 covers the edge of the liquid crystal panel 130 and is fastened to the mold frame 110. In detail, the top chassis 150 exposes the display area of the color filter substrate 135 while pressing the edge of the color filter substrate 135 and is fastened to the sidewall of the mold frame 110.

As described above, according to the present invention, when the electromagnetic wave emitted from the lamp unit flows toward the liquid crystal panel, the ground pattern disposed on the thin film transistor substrate and the auxiliary ground pattern disposed on the color filter substrate absorb the electromagnetic waves. The absorbed electromagnetic wave is induced and grounded toward the ground wiring of the gate printed circuit board which is electrically connected to the dummy wiring along the dummy wiring electrically connected to the ground pattern. Therefore, wave noise is not generated in the horizontal direction of the liquid crystal panel. As a result, the image quality of the liquid crystal panel is prevented from being lowered due to the interference of the electromagnetic waves.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

1 is a perspective view of a liquid crystal panel assembly according to an embodiment of the present invention.

2 is a partial cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: liquid crystal display 110: mold frame

120: backlight assembly 122: lamp unit

130: liquid crystal panel 131: thin film transistor substrate

134: grounding pattern 135: color filter substrate

139: auxiliary ground pattern 150: top chassis

160: gate printed circuit board 164: ground wiring

170: flexible circuit board 174: output wiring

176: input wiring 178: dummy wiring

Claims (7)

A liquid crystal comprising a thin film transistor substrate including a ground pattern, a color filter substrate disposed to face the thin film transistor substrate, a color filter substrate including color pixels, and a liquid crystal layer disposed between the thin film transistor substrate and the color filter substrate. panel; A printed circuit board including driving elements for driving the liquid crystal panel and a ground wiring; And And a flexible circuit board electrically connecting the ground pattern and the ground wiring. The color filter substrate of claim 1, wherein the color filter substrate further includes an auxiliary ground pattern corresponding to the ground pattern. And the ground pattern and the auxiliary ground pattern are electrically connected to each other. 3. The liquid crystal panel assembly of claim 2, wherein the ground pattern and the assistant ground pattern are disposed outside the region corresponding to the liquid crystal layer among the thin film transistor substrate and the color filter substrate, respectively. The method of claim 1, wherein the flexible circuit board An input wiring electrically connected to the printed circuit board; An output wiring electrically connected to the liquid crystal panel; And And a dummy wiring electrically connecting the ground pattern and the ground wiring to provide a ground path for electromagnetic waves transmitted from the outside. The method of claim 1, wherein the thin film transistor substrate Transparent substrate; A plurality of gate lines disposed on the transparent substrate; Source lines on the transparent substrate so as to intersect the gate lines; Pixel electrodes disposed in pixel regions surrounded by the gate lines and source lines; And And switching elements configured to apply a data signal applied from the source lines to the pixel electrode according to selection signals applied from the gate lines. And the ground pattern is disposed in parallel with the gate lines at one edge of the transparent substrate. Mold frame having a receiving portion; A backlight assembly including a lamp unit disposed on a side surface of the accommodating part, a reflecting plate, a light guide plate, and an optical sheet disposed sequentially on a base surface of the accommodating part; A thin film transistor substrate including a ground pattern disposed in an area, a color filter substrate facing the thin film transistor substrate and including color pixels, and a liquid crystal layer disposed between the thin film transistor substrate and the color filter substrate. A liquid crystal panel; A printed circuit board including driving elements for generating a panel driving signal applied to the liquid crystal panel and a ground wiring; A flexible circuit board having a dummy wiring to electrically connect the ground pattern and the ground wiring to provide a ground path; And And a top chassis covering an edge of the liquid crystal panel and fastened to the mold frame. The method of claim 6, wherein the flexible circuit board An input wiring to receive the panel driving signal from the printed circuit board; An output wiring for applying the panel driving signal to the liquid crystal panel; And And a dummy wiring electrically connecting the ground pattern and the ground wiring to provide a ground path for electromagnetic waves emitted from the lamp unit.