Liquid crystal display device associated with touch panel

Patent metadata

Field	Value
Publication number	US-10921936-B2
Application number	US-96715810-A
Country	US
Kind code	B2
Filing date	Dec 14, 2010
Priority date	Jun 10, 2010
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

To block noise and achieve slimness and integration, a liquid crystal display device includes according to an embodiment a liquid crystal panel including first and second substrates and a liquid crystal layer formed therebetween, a shielding electrode formed throughout the entire rear surface of the second substrate of the liquid crystal panel, a first polarizing plate formed on the shielding electrode, a third substrate formed above the first polarizing plate and including intersecting first and second electrodes, a touch FPC including a touch drive IC to control driving and sensing of the first and second electrodes, and a printed circuit board formed at one side of the liquid crystal panel and generating a main panel control signal to control driving of the liquid crystal panel, a touch control signal to control the touch drive IC, and a voltage signal.

First claim

What is claimed is:

1. A liquid crystal display device associated with a touch panel, the liquid crystal display device comprising:
a liquid crystal panel including a first substrate and a second substrate positioned opposite to each other and a liquid crystal layer between the first and second substrates;
a shielding electrode throughout the entire rear surface of the second substrate of the liquid crystal panel;
a first polarizing plate on the shielding electrode;
a third substrate having a first surface:
a plurality of first electrodes and second electrodes intersecting each other on the first surface of the third substrate, wherein the first surface of the third substrate is opposite to the first polarizing plate;
a plurality of touch pads respectively corresponding to the first and second electrodes and not overlapping the first polarizing plate at one edge of the first surface of the third substrate,
a touch flexible printed circuit (FPC) connected to the plurality of touch pads to control driving and sensing of the first and second electrodes;
a driving pad electrode and a ground pad electrode respectively on one surface of the first substrate, wherein the driving pad electrode and the ground pad electrode are not overlapping the second substrate and the first polarizing plate;
a main panel FPC located at the one surface of the first substrate and connected to the driving pad electrode to control driving of the liquid crystal panel; and
a printed circuit board between the main panel FPC and the touch FPC,
wherein the main panel FPC is connected to the printed circuit board by a first connector for supplying a voltage signal of a designated level together with a main panel control signal to the main panel FPC, and the touch FPC is connected to the printed circuit board by a second connector for supplying a touch control signal,
wherein a touch drive IC on the touch FPC faces to the one surface of the first substrate on which the driving pad electrode and the ground pad electrode are formed,
wherein at least one of the first and second electrodes faces to the shielding electrode by interposing the first polarizing plate between the at least one of the first and second electrodes and the shielding electrode, and
wherein the third substrate is configured to serve as a protective cover.

2. The liquid crystal display device according to claim 1 , wherein the voltage signal of the designated level is a constant voltage or a ground voltage and wherein the voltage signal of the designated level is transmitted to the shielding electrode through the main panel FPC and the ground pad electrode, and wherein an electrical connection between the ground pad electrode and the shielding electrode is provided by an Ag dot material provided at side surfaces of the shielding electrode and the second substrate, and the Ag dot material is not in contact with an upper surface of the shielding electrode.

3. The liquid crystal display device according to claim 1 , wherein the shielding electrode and the first and second electrodes are transparent electrodes.

4. The liquid crystal display device according to claim 3 , wherein the shielding electrode has a sheet resistance of less than 100Ω/□.

5. The liquid crystal display device according to claim 1 , wherein the third substrate is a glass substrate or a transparent insulating film.

6. The liquid crystal display device according to claim 5 , wherein an adhesive layer is interposed between the third substrate and the first polarizing plate.

7. The liquid crystal display device according to claim 5 , wherein an adhesive agent applied in a closed loop shape along the edge of the first polarizing plate is formed between the third substrate and the first polarizing plate.

8. The liquid crystal display device according to claim 7 ,
wherein an air gap is formed within an inner space between the third substrate and the first polarizing plate.

9. The liquid crystal display device according to claim 1 , wherein a thin film transistor array is provided in the first substrate, and a color filter array is provided in the second substrate.

10. The liquid crystal display device according to claim 1 , further comprising a cover glass on the third substrate.

11. The liquid crystal display device according to claim 1 , wherein the main panel FPC includes a first side received by the one surface of the first substrate, and
wherein the driving pad electrode is disposed between the one surface of the first substrate and the first side of the main panel FPC.

12. The liquid crystal display device according to claim 1 , wherein an electrical connection between the ground pad electrode and the shielding electrode is formed by a conductive tape, and
wherein the conductive tape on the shielding electrode is covered by the first polarizing plate.

13. The liquid crystal display device according to claim 1 , wherein an electrical connection between the ground pad electrode and the shielding electrode is formed by bonding an Ag dot from side surfaces of the shielding electrode and the second substrate to the ground pad electrode, and
wherein the Ag dot is not in contact with an upper surface of the shielding electrode.

14. The liquid crystal display device according to claim 1 , wherein the touch FPC includes a first side received by the first surface of the third substrate and a second side for receiving the touch drive IC, and wherein the plurality of touch pads are between the first surface of the third substrate and first side of the touch FPC.

15. The liquid crystal display device according to claim 1 , further comprising an insulating film formed between the first electrodes and the second electrodes.

16. The liquid crystal display device according to claim 1 , wherein the third substrate protects the first and second electrodes, and
wherein the shielding electrode is electrically insulated from the first and second electrodes by the first polarizing plate.

Assignees

• Kim Tae Hwan
• Hwang Min Woo
• Lg Display Co Ltd

Inventors

• Kim Tae-Hwan
• Hwang Min-Woo

Classifications

• G09G2300/0426

  Layout of electrodes and connections · CPC title

• G09G2330/06

  Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation · CPC title

• G09G3/3611

  Control of matrices with row and column drivers · CPC title

• G06F3/0445 Primary

  using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer · CPC title

• G06F3/044 Primary

  by capacitive means · CPC title