LIQUID CRYSTAL DISPLAY DEVICE

• US 20100156862A1
• Filed: 12/02/2009
• Published: 06/24/2010
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Koo, Hoe Woo, Kim, Bum sik, Kim, Lee Young
• Granted Patent: US 8,786,584 B2
• Time in Patent Office: Days
• US Class Current: 345/206
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/0291 Details of output amplifiers or buffers arranged for use in a driving circuit
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G11C 19/18 using capacitors as main elements of the stages if capacitors are used as auxiliary stage in between main stages with other elements, the latter take precedence; G11C19/005 takes precedence
• CPC Class Codes: G11C 19/28 using semiconductor elements G11C19/14, G11C19/36 take precedence

Abstract

A liquid crystal display device is disclosed. The liquid crystal display device includes an output portion which is configured to include an output transistor having a large capacitor component. As such, the liquid crystal display device can enhance the response speed of liquid crystal.

Claims

1. A liquid crystal display device comprising:

a display panel configured to display an image, the display panel including a plurality of gate lines and a plurality of data lines;

a data driver configured to supply the data lines of the liquid crystal panel with data signals corresponding to the image; and

a gate driver on the liquid crystal panel and including a plurality of shift registers, which are configured to apply output signals sequentially shifted from a start pulse to the gate lines, each of the shift registers including;

an output portion having an output transistor which includes;

a gate electrode responsive to a voltage on a first node;

a source electrode receiving a clock signal;

a drain electrode connected to the respective gate line and configured to apply the clock signal from the source electrode to the respective gate line according to the voltage on the first node; and

a top electrode disposed on an uppermost layer and connected to the gate electrode, and

a control portion that controls the output portion.

2. The liquid crystal display device claimed as claim 1, wherein the output transistor includes:

the gate electrode formed on a substrate;

a gate insulating film formed on the substrate with the gate electrode;

a semiconductor layer formed, opposite the gate electrode, on the substrate with the gate insulating film;

the source and drain electrodes being separated from each other on the semiconductor layer;

a passivation layer formed on the source and drain electrodes; and

the top electrode formed, opposite the semiconductor layer, on the passivation layer and electrically connected to the gate electrode through a contact hole on the passivation layer.

3. The liquid crystal display device claimed as claim 1, wherein the top electrode comprises a transparent metal material.

4. The liquid crystal display device claimed as claim 1, wherein the top electrode comprises indium-tin-oxide.

5. The liquid crystal display device claimed as claim 1, wherein the top electrode comprises the same metal material as the gate electrode.

6. The liquid crystal display device claimed as claim 1, wherein the top electrode comprises the same metal material as the source and drain electrodes.