Protection device for gate integrated circuit, gate driver, liquid crystal display including the same and method of protecting a gate IC in a display
A gate IC protection device that protects a gate IC from damage and allows image to be generated normally even when an abnormal vertical synchronization start signal is received is presented, along with a gate driver and a liquid crystal display employing the gate IC protection device. A method of protecting a gate IC in a display device is also presented. The gate IC protection device includes a vertical synchronization start signal converting unit and a signal delay unit. The vertical synchronization start signal converting unit receives a first vertical synchronization start signal and a level control signal, performs a predetermined logic operation thereon, and outputs a second vertical synchronization start signal. The signal delay unit receives the second vertical synchronization start signal and outputs the level control signal that is fed back to the vertical synchronization start signal converting unit in synchronization with a gate clock signal.
1 . A gate integrated circuit (IC) protection device comprising:
a vertical synchronization start signal converting unit having:
a first input for receiving a first vertical synchronization start signal and a level control signal,
a logic circuit for performing a predetermined logic operation thereon, and
a first output for outputting a second vertical synchronization start signal; and
a signal delay unit having:
a second input for receiving the second vertical synchronization start signal and
a second output for outputting the level control signal that is fed back to the vertical synchronization start signal converting unit in synchronization with a gate clock signal.
2 . The gate IC protection device of claim 1 , wherein the vertical synchronization start signal converting unit comprises:
an inverter receiving the level control signal and outputting an inverted level control signal; and
an AND gate receiving the first vertical synchronization start signal and the inverted level control signal and outputting the second vertical synchronization start signal.
3 . The gate IC protection device of claim 1 , wherein the signal delay unit includes a D-flip-flop.
4 . A gate driver comprising:
a vertical synchronization start signal converting unit having:
a first input for receiving a first vertical synchronization start signal and a level control signal,
a logic circuit for performing a predetermined logic operation thereon, and
a first output for outputting a second vertical synchronization start signal; and
a gate integrated circuit (IC) having:
a second input for receiving the second vertical synchronization start signal; and
a second output for outputting gate ON/OFF signals in synchronization with a gate clock signal, wherein one of the gate ON/OFF signals is fed back to the vertical synchronization start signal converting unit as the level control signal.
5 . The gate driver of claim 4 , wherein the gate IC comprises a plurality of D-flipflops, wherein each of the D-flipflops outputs the gate ON/OFF signals to one of the gate lines, and wherein one of the D-flipflops feeds the level control signal back to the vertical synchronization start signal converting unit in synchronization with to the gate clock signal.
6 . The gate driver of claim 4 , wherein the vertical synchronization start signal converting unit comprises:
an inverter receiving the level control signal and outputting an inverted level control signal; and
an AND gate receiving the first vertical synchronization start signal and the inverted level control signal and outputting the second vertical synchronization start signal.
7 . A liquid crystal display (LCD) comprising:
a timing controller producing a first vertical synchronization start signal and a gate clock signal;
a gate IC protection device outputting a second vertical synchronization start signal of a logic low when the first vertical synchronization start signal is held high for more than a predetermined time period;
a gate driver receiving the second vertical synchronization start signal and outputting gate ON/OFF signals in synchronization with the gate clock signal; and
a liquid crystal panel assembly driving pixels using the gate ON/OFF signals and displaying a predetermined image.
8 . The LCD of claim 7 , wherein the gate IC protection device comprises:
a vertical synchronization start signal converting unit having:
a first input for receiving the first vertical synchronization start signal and a level control signal,
a logic circuit for performing a predetermined logic operation thereon, and
a first output for outputting the second vertical synchronization start signal, and
a signal delay unit having:
a second input for receiving the second vertical synchronization start signal, and
a second output for outputting the level control signal back that is fed back to the vertical synchronization start signal converting unit in synchronization with the gate clock signal.
9 . The LCD of claim 8 , wherein the vertical synchronization start signal converting unit comprises:
an inverter receiving the level control signal and outputting an inverted level control signal, and
an AND gate receiving the first vertical synchronization start signal and the inverted level control signal and outputting the second vertical synchronization start signal.
10 . The LCD of claim 8 , wherein the signal delay unit includes a D-flip-flop.
11 . The LCD of claim 7 , wherein the predetermined time period is a time taken for a gate line to be turned on.
12 . A liquid crystal display (LCD) comprising:
a timing controller providing a first vertical synchronization start signal and a gate clock signal;
a gate driver including a gate IC protection device outputting a second vertical synchronization start signal of a logic low when the first vertical synchronization start signal is held high for more than a predetermined time period, and outputting gate ON/OFF signals in synchronization with the gate clock signal; and
a liquid crystal panel assembly driving pixels using the gate ON/OFF signals and displaying a predetermined image.
13 . The LCD of claim 12 , wherein the gate IC protection device comprises:
a vertical synchronization start signal converting unit having:
a first input for receiving the first vertical synchronization start signal and a level control signal,
a logic circuit for performing a predetermined logic operation thereon, and
a first output for outputting the second vertical synchronization start signal, and
a signal delay unit having:
a second input for receiving the second vertical synchronization start signal; and
a second output for outputting the level control signal that is back to the vertical synchronization start signal converting unit in synchronization with the gate clock signal.
14 . The LCD of claim 13 , wherein the vertical synchronization start signal converting unit comprises:
an inverter receiving the level control signal and outputting an inverted level control signal; and
an AND gate receiving the first vertical synchronization start signal and the inverted level control signal and outputting the second vertical synchronization start signal.
15 . The LCD of claim 14 , wherein the gate driver comprises a plurality of D-flipflops, wherein each of the D-flipflops outputs the gate ON/OFF signals to one of gate lines, and wherein the signal delay unit includes one of the D-flip-flops.
16 . The LCD of claim 12 , wherein the predetermined time period is a time taken for a gate line to be turned on.
17 . A liquid crystal display (LCD) comprising:
a timing controller including a clock generator producing a gate clock signal and a first vertical synchronization start signal, and a gate IC protection device outputting a second vertical synchronization start signal of a logic low when the first vertical synchronization start signal is held high for more than a predetermined time period;
a gate driver receiving the second vertical synchronization start signal and outputting gate ON/OFF signals in synchronization with the gate clock signal; and
a liquid crystal panel assembly driving pixels using the gate ON/OFF signals and displaying a predetermined image.
18 . The LCD of claim 17 , wherein the gate IC protection device comprises:
a vertical synchronization start signal converting unit having:
a first input for receiving the first vertical synchronization start signal and a level control signal,
a logic circuit for performing a predetermined logic operation thereon, and
a first output for outputting the second vertical synchronization start signal; and
a signal delay unit having:
a second input for receiving the second vertical synchronization start signal; and
a second output for outputting the level control signal that is fed back to the vertical synchronization start signal converting unit in synchronization with the gate clock signal.
19 . The LCD of claim 18 , wherein the vertical synchronization start signal converting unit comprises:
an inverter receiving the level controls signal and outputting an inverted level control signal, and
an AND gate receiving the first vertical synchronization start signal and the inverted level control signal and outputting the second vertical synchronization start signal.
20 . The LCD of claim 18 , wherein the signal delay unit includes a D-flip-flop.
21 . The LCD of claim 17 , wherein the predetermined time period is a time taken for a gate line to be turned on.
22 . A method of protecting a gate IC in a display device, the method comprising:
receiving a first vertical synchronization signal and a level control signal; and
performing a logic operation on the first vertical synchronization start signal and the level control signal to generate a second vertical synchronization start signal;
wherein the level control signal is generated using the second synchronization start signal.