Display apparatus

A display apparatus includes a display panel that displays an image in response to a data voltage, a data driving unit that outputs the data voltage in response to a driving signal, and a printed circuit board that outputs the driving signal and that has a static electricity discharge circuit. The discharge circuit discharges high-voltage static electricity, which is introduced into the data driving unit, to ground. Accordingly, the display apparatus prevents the data driving unit from being damaged by the high-voltage static electricity.

CROSS-REFERENCE TO RELATED APPLICATION

This application relies for priority upon Korean Patent Application No. 2008-66537 filed on Jul. 9, 2008, the contents of which are herein incorporated by reference in their entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a display apparatus. More particularly, the present disclosure relates to a display apparatus capable of protecting internal driving chips from high-voltage static electricity

2. Discussion of Related Art

Recently, liquid crystal displays (LCDs) have been extensively used due to their inherent advantages such as slimness, light weight and low power consumption. The LCD includes a controller that generates and outputs control signals, a data driving chip that outputs data signals in response to the control signals, and a liquid crystal display panel that displays images in response to the data signals.

The data driving chip is electrically connected to one end of the liquid crystal display panel and constitutes a panel module together with the liquid crystal display panel. The panel module is entirely shielded by a case typically formed of metal, except for the front surface of the liquid crystal display panel that displays the images.

Unlike the case, however, the liquid crystal display panel includes nonmetallic material, so static electricity is induced to the liquid crystal display panel. Such static electricity is introduced into the data driving chip attached to the liquid crystal display panel, causing damage to the data driving chip. In addition, the static electricity applied to the data driving chip is introduced into the controller that is electrically connected to the data driving chip, so that other internal circuit devices of the controllers are also damaged by the static electricity.

SUMMARY

Therefore, an exemplary embodiment of the present invention provides a display apparatus capable of protecting internal circuit devices from damages due to static electricity.

In an exemplary embodiment of the present invention, a display apparatus includes a display panel module that displays an image and a receptacle that receives the display panel module.

The display panel module includes a display panel, a data driving unit, a gate driving unit, and a printed circuit board. The display panel displays the image in response to a data voltage and a gate voltage. The data driving unit receives first and second driving signals and outputs the data voltage in response to the first driving signal. The gate driving unit receives the second driving signal from the data driving unit and outputs the gate voltage in response to the second driving signal. The printed circuit board includes a discharge circuit that outputs the first and second driving signals to the data driving unit and discharges static electricity introduced into the data driving unit toward the receptacle that receives the display module.

According to the display apparatus of the exemplary embodiment, the discharge circuit is provided on the printed circuit board to discharge high-voltage static electricity, which is introduced into the data driving unit, toward a receptacle housing a display panel module. Because the high-voltage static electricity is discharged toward the receptacle, the data driving unit can be protected from damage caused by the high-voltage static electricity.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1is a perspective view showing an exemplary embodiment of a display panel module500according to the present invention, andFIG. 2is a view showing an exemplary embodiment of a discharge circuit illustrated inFIG. 1. InFIG. 1, a control printed circuit board700, hereinafter, referred to as a control board, which is electrically connected to the display panel module500, is shown together with the display panel module500. In addition, data driving units200including six data driving chips220, respectively, are shown inFIG. 1. Thus, six interconnections are provided to transfer an analog supply voltage, which is supplied from the control board700, to the six data driving chips220. As shown inFIG. 1, six discharge circuits410are provided to electrically connect six first driving interconnections SL1, respectively, to a single third driving interconnection SL3. In order to facilitate explanation, one first driving interconnection SL1, one data driving chip220and one base film210, on which the data driving chip220is mounted, are shown inFIG. 2as an example.

Referring toFIGS. 1 and 2, the display panel module500receives image signals, control signals, and driving signals including a driving voltage from the control board700. The control board700is electrically connected to the display panel module500. That is, an electrical connector710of the control board700is electrically connected to an electrical connector430of the display panel module500through a plurality of signal lines600. A timing controller720and a DC-DC converter730are provided on the control board700. The timing controller720generates and outputs the image signals and control signals to the display panel module500. The DC-DC converter730receives a supply voltage from an external device (not shown) to generate and output the driving voltage used to drive the display panel module500. The driving voltage includes a digital driving voltage and an analog supply voltage. The digital driving voltage and analog supply voltage are applied to the data driving units200provided in the display panel module500. The digital driving voltage is used to drive an internal logic (not shown) of the data driving units200. The analog supply voltage serves as a reference voltage to generate a data voltage that is output from the data driving units200. That is, the data driving units200output a gray scale voltage, which corresponds to the image signal, as the data voltage for the pixels. The gray scale voltage is one of a plurality of gray scale voltages that are generated by dividing a potential difference between the analog supply voltage and a ground voltage.

Hereinafter, the display panel module500will be described in detail.

The display panel module500includes the discharge circuits410capable of rapidly discharging static electricity applied to the data driving units200from the outside. By action of the discharge circuits410, the data driving circuits200can be protected from damage caused by the static electricity. In addition, the static electricity applied to the data driving units200can be prevented from being transferred to the control board700through the signal lines600. Thus, circuit devices provided on the control board700can be prevented from being damaged by the static electricity. To this end, the display panel module500includes a display panel100, the data driving units200, the gate driving units300, and a data printed circuit board400, hereinafter referred to as a data board, on which the discharge circuits410are provided.

The display panel100displays images in response to the data voltage and gate voltage. In the present exemplary embodiment, the liquid crystal display panel will be described as an example of the display panel, however, the present invention is not limited thereto.

The liquid crystal display panel100includes an array substrate110, an opposite substrate120facing the array substrate110, and a liquid crystal layer115interposed between the array substrate110and the opposite substrate120. A plurality of data lines DL receiving the data voltage from the data driving units200and a plurality of gate lines GL receiving the gate voltage from the gate driving units300are aligned on the array substrate110. The data lines DL cross the gate lines GL while being insulated from the gate lines GL. A plurality of pixel areas are defined by the data lines DL and the gate lines GL. A thin film transistor (not shown) and a pixel electrode (not shown) electrically connected to the thin film transistor are provided in each pixel area of the liquid crystal display panel100. The thin film transistor is electrically connected to the corresponding gate line GL and data line DL to apply the data voltage to the pixel electrode in response to the gate voltage that is input through the corresponding gate line GL. The opposite substrate120is provided thereon with a color filter (not shown) and a common electrode (not shown). The color filter is provided in a display area of the array substrate110, that is, the color filter is provided corresponding to the pixel area. The common electrode faces the pixel electrode while interposing the liquid crystal layer115therebetween. A liquid crystal capacitor (not shown) is defined by the common electrode, the liquid crystal layer115and the pixel electrode.

The data driving units200receive first and second driving signals from the data board400and output the data voltage to the liquid crystal display panel100by using the first driving signal, hereinafter referred to as an analog supply voltage. Each data driving unit200includes a first base film210, and a data driving chip220mounted on the first base film210. For instance, each data driving chip220can be mounted on each base film210through a chip-on-film method (COF). One end of the first base film210is electrically attached to a peripheral area of the liquid crystal display panel100. Each data driving chip220mounted on the first base film210is electrically connected to the corresponding data line DL through an interconnection (not shown) formed on the first base film210.

The data driving chips220receive the analog supply voltage of about 15 volts from the data board400to generate the data voltage. Because the digital driving voltage used to drive the internal logic of the data driving chips200is about 3.3V, the analog supply voltage (15V) used to generate the data voltage is relatively high. Therefore, in order to prevent an abnormal analog supply voltage that exceeds 15V, an over-voltage protection circuit (not shown) is provided in the data driving chips220.

As described above in relation to problems in the related art, if high-voltage static electricity of about 15 kV is applied through the liquid crystal display panel100, the data driving chips220are primarily damaged. More specifically, the over-voltage protection circuit provided in the data driving chips220is damaged. That is, the static electricity is applied to input/output terminals of the analog supply voltage through the surface of the data driving chips220, so that the over-voltage protection circuit connected to the input/output terminals of the analog supply voltage is damaged. Further, the static electricity causes physical damage to the first base films210on which the data driving chips220are mounted. Accordingly, in the present exemplary embodiment, the discharge circuits410are provided on the data board400, which is electrically connected to the other end of the first base films210constituting the data driving units200, in order to discharge the static electricity More specifically, because the discharge circuits410are provided on the data board400directly connected to the data driving units200, the static electricity may be rapidly discharged. The discharge circuits410will be described hereinbelow in detail when explaining the data board400.

Each gate driving unit300shown inFIG. 1includes a second base film310, and a gate driving chip320mounted on the second base film310. As described above, each gate driving chip320can be mounted on each base film310through the COF method, or electrically connected to the liquid crystal display panel100through a tape carrier package (TCP) method. The gate driving units300receive the second driving signal, hereinafter referred to as a gate signal, through one of the base films210of the data driving unit200, which is closely adjacent the gate driving units300.

The data board400receives the analog supply voltage (the first driving signal) and the gate signal (the second driving signal) from the control board700and then outputs the analog supply voltage and the gate signal to the data driving unit200. In addition, the data board400discharges the static electricity that is introduced to the data driving unit200through the liquid crystal display panel100. In more detail, the data board400includes first driving interconnections SL1, hereinafter referred to as an analog supply power interconnection, a second driving interconnection SL2, hereinafter referred to as a gate signal interconnection, to transmit the gate signal, a third driving interconnection SL3hereinafter referred to as a discharge interconnection, to guide the static electricity to the ground GND, and discharge circuits410to transmit the static electricity, which is transferred to the analog supply voltage interconnections SL1through the data driving unit200, to the discharge interconnection SL3. In the present exemplary embodiment, six discharge circuits410are provided to electrically connect six analog supply voltage interconnections SL1to one discharge interconnection SL3.

Referring toFIG. 2, each discharge circuit410includes a resistor R having a first terminal connected to a first input terminal IN1and a second terminal connected to a first output terminal OUT1. Thus, when the high-voltage static electricity is introduced into the data driving unit200, the high-voltage static electricity is rapidly discharged to the ground GND through the resistor R. As a result, the data driving unit200can be protected from damage caused by the static electricity, and the static electricity can not be introduced into the control board700, so that circuit devices formed on the control board700can be protected from the static electricity.

The resistor R may be a fixed resistor having a fixed resistance value or a variable resistor having a variable resistance value. Recently, the liquid crystal display is fabricated in a small size, so the size of the data board400has become gradually reduced. Thus, when taking the size of the data board400into consideration, the fixed resistor is preferable because the fixed resistor enables a circuit configuration in a relatively narrow area. The resistance value of the resistor R can be variously set by a system designer. If the resistance value of the resistor R is excessively low, however, leakage current may occur through the resistor R. In this case, an abnormal analog supply voltage, for instance, a voltage much less than 15V is applied to the data driving unit200through the analog supply voltage interconnection, so that the data driving unit200outputs the abnormal data voltage. In contrast thereto, if the resistance value of the resistor R is excessively high, the static electricity will not be discharged through the resistor R. Therefore, a resistor R having an excessively high resistance value may not provide a normal discharge path. In this regard, the resistance value must be set with serious consideration. For example, the resistor R may have a resistance value in the range of about 100MΩ to about 300MΩ.

FIG. 3is a circuit diagram of an exemplary embodiment of a discharge circuit420according to the present invention.

Referring toFIG. 3, the discharge circuit420according to another exemplary embodiment of the present invention includes a second input terminal IN2connected to the analog supply voltage interconnection SL1, a second output terminal OUT2connected to the discharge interconnection SL3that is connected to ground, and first and second diodes D1and D2connected in parallel with opposite polarities between the second input terminal IN2and the second output terminal OUT2. More specifically, an anode of the first diode D1is electrically connected to the ground GND through the second output terminal OUT2, and a cathode of the first diode D1is electrically connected to the analog supply voltage interconnection SL1through the second input terminal IN2. In addition, an anode of the second diode D2is electrically connected to the analog supply voltage interconnection SL1through the second input terminal IN2, and a cathode of the second diode D2is electrically connected to the ground GND through the second output terminal OUT2.

If a normal analog supply voltage, which is lower than a threshold voltage of the second diode D2, is applied to the analog supply voltage interconnection SL1, the second diode D2is turned off. Thus, the analog supply voltage interconnection SL1and the discharge interconnection SL3are electrically open. In contrast, if static electricity having a high-voltage, which is higher than the threshold voltage of the second diode D2, is applied to the analog supply voltage interconnection SL1, the second diode D2is turned on. Thus, the analog supply voltage interconnection SL1and the discharge interconnection SL3are electrically shorted, so that the high-voltage static electricity is discharged to the ground GND through the discharge interconnection SL3. Therefore, the high-voltage static electricity introduced into the data driving unit200is rapidly discharged to the ground GND. In addition, the high-voltage static electricity may not be introduced into the control board700, so that circuit devices formed on the control board700can be prevented from being damaged.

FIG. 4is an exploded perspective view showing an exemplary embodiment of a display apparatus according to the present invention.

AlthoughFIG. 4shows a liquid crystal display1000as an example of various display apparatuses, the present invention is not limited thereto. Exemplary embodiments of the present invention are applicable for other display apparatuses, such as a plasma display panel (PDP) and an organic light emitting diode (OLED), in addition to the liquid crystal display1000. In the following description, the same reference numerals as used above will be used to refer to the same elements and detailed description thereof will be omitted in order to avoid redundancy. Unlike the data driving unit200shown inFIG. 1, in which the data driving unit200includes six base films210and six data driving chips220mounted on the six base films210, respectively, the data driving unit200shown inFIG. 4includes five base films210and five data driving chips220mounted on the five base firms210, respectively. In addition, the gate driving unit300shown inFIG. 1is omitted for simplicity in the showing ofFIG. 4.

Referring toFIG. 4, the liquid crystal display1000includes the display panel module100, which has been described with reference toFIGS. 1 to 3, and a receptacle20that receives the display panel module. In addition, the liquid crystal display1000further includes a chassis10.

The display panel module includes discharge circuits410provided on the data board400. The data board400having the discharge circuits410is accommodated in the receptacle20.

The receptacle20includes a material having high strength, such as metal, for example, aluminum. The data board400is connected to bent base films210and is fixed to a rear surface of the receptacle20. The receptacle20is electrically connected to the discharge interconnection SL3provided on the data board400, so that the receptacle20may serve as the ground GND. Thus, the high-voltage static electricity introduced into the data driving unit200is discharged to the surface of the receptacle20, which serves as the ground GND, by way of the analog supply voltage interconnection SL1, the discharge circuits410, and the discharge interconnection SL3provided on the data board400. AlthoughFIG. 4shows the discharge interconnection SL3connected to one side of the receptacle20through a predetermined interconnection L, the discharge interconnection SL3can be connected to the other side or the rear side of the receptacle20.

The chassis10presses a peripheral portion of the liquid crystal display panel100of the display panel module and is fixed to the receptacle20. Thus, the chassis10prevents the liquid crystal display panel100from becoming separated.

In other words, the high-voltage static electricity introduced into the data driving unit200may be rapidly discharged to the surface of the receptacle20through the discharge circuits410provided on the data board400. As a result, the data driving unit200may be protected from damage caused by the high-voltage static electricity, and the high-voltage static electricity is prevented from being introduced into the control board700through the data board400, so that the circuit devices provided on the control board700are also prevented from being damaged.

Meanwhile, although not shown inFIGS. 1 to 4, a backlight assembly including a reflective plate (not shown), a light guide plate (not shown), a lamp (not shown) and optical sheets (not shown) can be provided between the liquid crystal display panel100and the receptacle20. In that case, the backlight assembly is accommodated in the receptacle20together with the liquid crystal display panel100.