Integrated LCD touch screen to determine a touch position based on an induced voltage superimposed on both the scan signal of the gate line and a timing pulse of the signal line

• US 8,749,511 B2
• Filed: 08/25/2009
• Issued: 06/10/2014
• Est. Priority Date: 09/05/2008
• Status: Expired due to Fees

• Current Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.)
• Original Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.)
• Inventors: Wang, Zheng, Ryu, Jai-il
• Primary Examiner(s): Nguyen, Chanh
• Assistant Examiner(s): LINGARAJU, NAVIN B
• Application Number:
  US12/546,843
• Publication Number:
  US 20100060600A1
• Time in Patent Office: 1,750 Days
• Field of Search: 345173-184, 349/12, 178 1803- 1907
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

The present invention provides an array substrate, a liquid crystal display device comprising the same, and a method for forming the same. The array substrate comprises a gate line, a data line, a signal line and a pixel electrode formed thereon. The gate line intersects the data line to define a plurality of pixel regions in which the pixel electrodes are formed. Each of the pixel electrodes overlaps the signal line to form a first sensing capacitor and overlaps the gate line to form a second sensing capacitor.

Claims

1. A liquid crystal display device having a touch screen function comprising:

an array substrate having a gate line, a data line, a signal line and a pixel electrode formed thereon, the gate line intersecting the data line to define a pixel region in which the pixel electrode is formed,

wherein the signal line is parallel with the data line, the gate line transmits a scan signal to thin film transistors,

wherein a same pixel region has a first sensing capacitor and a second sensing capacitor, the pixel electrode overlaps the signal line to form the first sensing capacitor and the pixel electrode also overlaps the gate line to form the second sensing capacitor;

the gate line and the signal line are connected to a touch processing section;

when the liquid crystal display device is touched, a change of a pixel electrode voltage is resulted, the change of the pixel electrode voltage is reflected on the first sensing capacitor formed on the signal line to cause a small change of voltage on the signal line, the small change of voltage is superimposed on a pulse signal transmitted on the signal line to obtain a voltage signal on the signal line, similarly, the change of the pixel electrode voltage is reflected on the second sensing capacitor formed on the gate line to cause another small change of voltage on the gate line, the another small change of voltage is superimposed on the scan signal transmitted on the gate line to obtain a voltage signal on the gate line; and

the touch processing section receives the voltage signal on the signal line and the voltage signal on the gate line and determines the touch position based on the voltage signal on the signal line and the voltage signal on the gate line.

2. The liquid crystal display device of claim 1, wherein the touch processing section comprises:

a first touch detecting module to determine whether the signal line is touched;

a second touch detecting module to determine whether the gate line is touched; and

a central processing module to determine the touch position based on the touched signal line and the touched gate line,

wherein the first touch detecting module is connected with the signal line, the second touch detecting module is connected with the gate line, and the central processing module is connected with the first and second touch detecting modules.

3. The liquid crystal display device of claim 2, wherein the first touching detecting module comprises a first signal amplifier and a first comparator, the first signal amplifier is connected with the signal line to amplify the voltage signal on the signal line, the first comparator is connected with the first signal amplifier to compare the amplified voltage signal of the signal line with a reference voltage signal of the signal line so as to determine whether the signal line is touched.

4. The liquid crystal display device of claim 2, wherein the second touching detecting module comprises a second signal amplifier and a second comparator, the second signal amplifier is connected with the gate line to amplify the voltage signal on the gate line, the second comparator is connected with the second signal amplifier to compare the amplified voltage signal of the gate line with a reference voltage signal of the gate line so as to determine whether the gate line is touched.

5. The liquid crystal display device of claim 1, wherein the signal line is connected with a narrow timing pulse generator.

6. The liquid crystal display device of claim 5, wherein the touch processing section comprises:

a first touch detecting module to determine whether the signal line is touched;

a second touch detecting module to determine whether the gate line is touched; and

a central processing module to determine the touch position based on the touched signal line and the touched gate line,

wherein the first touch detecting module is connected with the signal line, the second touch detecting module is connected with the gate line, and the central processing module is connected with the first and second touch detecting modules.

7. The liquid crystal display device of claim 6, wherein the first touching detecting module comprises a first signal amplifier and a first comparator, the first signal amplifier is connected with the signal line to amplify the voltage signal on the signal line, the first comparator is connected with the first signal amplifier to compare the amplified voltage signal of the signal line with a reference voltage signal of the signal line so as to determine whether the signal line is touched.

8. The liquid crystal display device of claim 6, wherein the second touching detecting module comprises a second signal amplifier and a second comparator, the second signal amplifier is connected with one gate line to amplify the voltage signal on the gate line, the second comparator is connected with the second signal amplifier to compare the amplified voltage signal of the gate line with a reference voltage signal of the gate line so as to determine whether the gate line is touched.