Driving circuit and liquid crystal display module having the same

A driving circuit of a liquid crystal display module includes a substrate, a driving chip, a plurality of circuit lines connected to the driving chip, and a dummy pattern disposed outside the circuit lines parallel thereto. The liquid crystal display module includes a display panel, and a driving circuit. The display panel includes an effective pixel region, a non-effective pixel region, a display device displaying an image in the effective pixel region, and signal lines connected to the display device and extending to the non-effective pixel region. The driving circuit includes a substrate, a driving chip, circuit lines, and a dummy pattern disposed outside the circuit lines parallel thereto. The circuit lines each have one end connected to the driving chip and the other end connected to the signal lines. Accordingly, the dummy pattern can reduce defective images caused by the circuit lines damaged by mechanical impact.

This application claims the benefit of the Korean Patent Application No. 2006-0060202, filed on Jun. 30, 2006, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a driving circuit, and a liquid crystal display module having the same.

2. Description of the Related Art

An electronic display device displays information generated from various electronic devices as an image. Recently, electronic display devices have been developed to have a large size and a thin profile. Furthermore, as a chip on flexible printed circuit (COF) technology has been developed, the electronic display device has a thinner profile.

The COF is manufactured by mounting a semiconductor chip directly on a film type circuit board. The COF is advantageous in that a film which is thinner than that of a related art tape carrier package (TCP) may be used, and leads to which a signal is applied may be arranged at intervals shorter than those in the TCP.

FIG. 1is a plan view illustrating a liquid crystal display (LCD) module employing the related art COF.FIG. 2Ais an enlarged perspective view of part A′ ofFIG. 1, andFIG. 2Bis a cross-sectional view taken along line II-II′ ofFIG. 1.

Referring toFIG. 1, a related art LCD module501includes a LCD panel510displaying an image. The LCD panel510includes driving circuits600for driving a display device therein. The driving circuits600are disposed on an edge of the LCD panel510.

Each of the driving circuits600includes a substrate630, a driving chip610, and circuit lines620. The driving chip610is disposed on the substrate630having a film shape, and the circuit lines620are electrically connected to the driving chip610disposed on the substrate630.

The driving circuit600transmits a driving signal processed by a printed circuit board (PCB) to the LCD panel510.

Referring toFIGS. 2A and 2B, the LCD panel510and the driving circuit600are electrically connected together by an anisotropic conductive film (ACF)640.

The LCD panel510includes a plurality of thin film transistors (TFTs) (not illustrated) and pixel electrodes (not illustrated) connected to the TFTs. The TFT provides a pixel voltage to the pixel electrode in response to a driving signal applied from the driving circuit600.

The LCD panel510includes signal lines525electrically connected to the thin film transistors, and pad portions520provided at respective ends of the signal lines525and electrically connected to the respective circuit lines620of the driving circuit600. Each circuit line620of the driving circuit600overlaps each signal line525of the LCD panel, and the circuit line620and the signal line525are electrically connected together by the ACF640. The ACF640includes fine conductive balls.

Since the related art driving circuit600is formed on the substrate630having the film shape, the driving circuit600is advantageous in that it can be bent or folded. Furthermore, since the driving circuit600can be folded or bent, the entire size of the LCD module501can be reduced.

However, when the driving circuit600is folded or bent, the circuit lines620formed on the driving circuit600may be damaged or cut.

FIG. 3Ais a plan view illustrating a related art LCD module having a PCB, andFIG. 3Bis an enlarged view of part ‘B’.

Referring toFIG. 3A, the LCD module501includes a plurality of driving circuits600on an edge of the LCD panel510, and a PCB700electrically connected to the driving circuits600.

The LCD panel510and the driving circuits600, and the driving circuit600and the PCB700are electrically connected together by anisotropic conductive films, respectively. To attach the PCB700to the driving circuit600with the anisotropic conductive film, heat and pressure are applied to the anisotropic conductive film. Also, after the PCB700and the driving circuit600are attached, the PCB700is cooled. Thus, the PCB700electrically connected to the driving circuit600expands when electrically connected to the driving circuit600, while it is heated, and contracts after the connection when it cools.

The expansion and contraction of the PCB700creates great stress at the LCD module501, and cracks and damages may occur to the PCB700and the driving circuit600by such stress.

Otherwise, when vibration and impact are applied to the PCB700and/or the driving circuit600, the PCB700and/or the driving circuit600may be easily damaged.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a driving circuit and an LCD module having the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a driving circuit capable of suppressing damage caused by stress, vibration, impact, and the like.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a driving circuit including: a substrate; a driving chip disposed on the substrate; a plurality of circuit lines connected to the driving chip; and a dummy pattern disposed outside the circuit lines parallel thereto.

In another aspect of the present invention, there is provided a liquid crystal display module including: a display panel including an effective pixel region, a non-effective pixel region disposed around the effective pixel region, a display device disposed in the effective pixel region and displaying an image, and signal lines connected to the display device and extending to the non-effective pixel region; and a driving circuit including a substrate, a driving chip disposed on the substrate, circuit lines each having one end connected to the driving chip and the other end being opposite to the one end and connected to the signal lines, and a dummy pattern disposed outside the circuit lines parallel thereto.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 4is a plan view illustrating an LCD module according to an embodiment of the present invention.FIG. 5Ais an enlarged view illustrating part of a driving circuit inFIG. 4, andFIG. 5Bis a cross-sectional view taken along line V-V′ inFIG. 4.

Referring toFIGS. 4,5A, and5B, a liquid crystal display (LCD) module1includes an LCD panel10having a display device for displaying an image, a printed circuit board (PCB)200processing an image signal generated from an information processing device and generating a driving signal, and a driving circuit100providing a driving signal to the LCD panel10.

The LCD panel10includes an effective pixel region (EPR), and a non-effective pixel region (NEPR). A plurality of display devices (not illustrated) is disposed on the EPR. The display device includes switching devices such as thin film transistors (TFT), and pixel electrodes electrically connected to the TFTs, respectively.

In order to supply to each TFT a driving signal generated from the driving circuit100, signal lines are connected to the TFT. The signal lines extend to the NEPR from the EPR of the LCD panel10.

Pad portions25electrically connected to circuit lines120of the driving circuit100are formed at ends of the signal lines, respectively.

At least one driving circuit100providing a driving signal to the display device is disposed in the NEPR of the LCD panel10.

The PCB700receives an image signal generated from the information processing device to generate a driving signal.

The driving circuit100includes a substrate130, a driving chip110, circuit lines120(depicted inFIG. 5A), and a dummy pattern160.

The substrate130is formed of a synthetic resin material having a small thickness, and has a rectangular shape substantially when viewed on the plane.

In detail, the substrate130is formed of a synthetic resin having a small thermal expansion coefficient, good flexibility, and a small thickness. An example of a material that may be used as the substrate130includes polyimide or the like.

The driving chip110is formed on the substrate130, and applies a driving signal to the display device disposed in a pixel region of the LCD panel10. The driving chip110may be mounted directly on the substrate130, for example, by a surface mounting technology (SMT), for example.

The circuit lines120electrically connect the PCB700with the driving chip110, and also electrically connect the driving chip110with the signal lines of the LCD panel10. Examples of a material that may be used as the circuit lines120include copper, silver, for example.

In this embodiment, after a metal layer is formed on the substrate130by a sputtering or plating method, the metal layer is patterned to form the circuit lines at very small intervals.

Referring to againFIG. 5B, the circuit lines120of the driving circuit100are electrically connected to the pad portions25formed at ends of the signal lines of the LCD panel10, respectively. Each circuit line120and each pad portion25are electrically connected by the anisotropic conductive film140.

The anisotropic conductive film140includes a resin having adhesiveness, and fine conductive balls included in the resin. The pad portion25and the circuit lines120are electrically connected together by the conductive balls.

Referring toFIG. 5Aagain, dummy patterns160are disposed on the substrate130of the driving circuit100.

The dummy pattern160according to one embodiment of the present invention is disposed outside the circuit lines120at a predetermined interval therefrom.

The dummy pattern disposed on the substrate130blocks and/or absorbs stress, vibration, impact and the like that are generated around the circuit lines120, thereby preventing cracks and damages of the circuit lines120from occurring.

In the present embodiment, the dummy pattern160may be electrically disconnected with the pad portion25.

In the present embodiment, the dummy pattern160may have a bar shape when viewed on the plane, and may be disposed substantially parallel to the circuit lines120. The dummy pattern160may have a shape bent at least once, or a zigzag shape. Also, the dummy pattern160may have a zigzag shape or a shape bent at a right angle.

Referring toFIG. 6, to efficiently absorb stress, vibration and impact, the dummy pattern160may be formed in a connection region where the circuit lines120and the pad portions25overlap each other.

Also, to more efficiently absorb stress, vibration and impact, the dummy pattern160may further include an impact absorbing portion165. The impact absorbing portion165may be formed by partially increasing an area of the dummy pattern160when viewed on the plane.

The impact absorbing portion165may have a semicircular plate shape when viewed on the plane. Otherwise, the impact absorbing portion165may have a triangular, quadrangular or polygonal shape when viewed on the plane.

In the present exemplary embodiment, the impact absorbing portion165may have various shapes. To remove static electricity generated around the circuit lines120, the dummy pattern160may further include a static-electricity removing pattern162. The static-electricity removing pattern165protrudes from a side of the dummy pattern160in the form of a saw tooth. The static-electricity removing pattern162may protrude from a side of the dummy pattern in the form of a bar, not the saw tooth.

In the present exemplary embodiment, the impact absorbing portion165is formed at one end of the dummy pattern160, and the static-electricity removing pattern162may be formed at the other end facing the one end of the dummy pattern160. The impact absorbing portion165and the static-electricity removing pattern162may be formed together at one end of the dummy pattern160.

In the driving circuit and the LCD module having the same according to an embodiment of the present invention, the dummy pattern that can absorb mechanical impact is provided at the driving circuit, so that exposure of the circuit lines to the mechanical impact can be minimized.

Accordingly, the dummy pattern may reduce defective images that may be generated from the LCD module as the circuit lines are damaged by the mechanical impact.