Display Device Having Touch Screen Panel

• US 20120081320A1
• Filed: 09/29/2011
• Published: 04/05/2012
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: HWANG, Intak, Cho, Namkyun
• Granted Patent: US 8,970,517 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A display device having a touch screen panel includes a display panel includes a common electrode; a touch screen panel including a plurality of first conductive patterns that are formed on one surface of the display panel and arranged in a first direction, and a plurality of second conductive patterns that are electrically insulated from the plurality of first conductive patterns and arranged in a second direction to cross over the first conductive patterns; a power source circuitry to supply a first common voltage to the common electrode and to supply a pulse voltage to at least one of the plurality of first and second conductive patterns; and a common voltage feedback circuit to remove an induction voltage induced to the common electrode by the pulse voltage supplied to the at least one of the plurality of first and second conductive patterns.

Claims

1. A display device having a touch screen panel, comprising:

a display panel including a common electrode;

a touch screen panel including a plurality of first conductive patterns that are formed on one surface of the display panel and arranged in a first direction, and a plurality of second conductive patterns that are electrically insulated from the plurality of first conductive patterns and arranged in a second direction to cross over the first conductive patterns;

a power source circuitry to supply a first common voltage to the common electrode and to supply a pulse voltage to at least one of the plurality of first and second conductive patterns; and

a common voltage feedback circuit to remove an induction voltage induced to the common electrode by the pulse voltage supplied to the at least one of the plurality of first and second conductive patterns.

2. The display device of claim 1, wherein the common voltage feedback circuit includes a differential circuit.

3. The display device claim 1, wherein the common voltage feedback circuit comprises:

a low pass filter to receive the pulse voltage from the power source circuitry and to reduce a high frequency gain of the pulse voltage; and

an operation amplifier to receive the pulse voltage in which the high frequency gain is reduced and a second common voltage from the common electrode, the second common voltage including the induction voltage, so that a third common voltage is generated to remove the induction voltage from the second common voltage.

4. The display device of claim 3, further comprising:

a first conductive pattern driving portion to sequentially supply the pulse voltage to the plurality of first conductive patterns to scan the plurality of first conductive patterns; and

a second conductive pattern driving portion to sequentially supply the pulse voltage to the plurality of second conductive patterns to scan the plurality of second conductive patterns after the scanning of the first conductive patterns are completed;

5. The display device claim 4, wherein the low pass filter comprises a capacitor connected to at least one of the first and second conductive pattern driving parts, and a first resistor connected to the capacitor in series, and

the operation amplifier comprises a non-inversion terminal to receive the second common voltage from the common electrode, an inversion terminal to receive the pulse voltage in which the high frequency gain is reduced from the low pass filter, and an output terminal to output the third common voltage to the common electrode.

6. The display device claim 5, wherein the common voltage feedback circuitry further comprises a second resistor connected between the inversion terminal of the operational amplifier and the output terminal of the operational amplifier.

7. The display device claim 2, wherein the differential circuit comprises:

a capacitor connected to at least one of first and second conductive pattern driving portions for the plurality of first and second conductive patterns;

a first resistor connected between the capacitor and a first node;

an operational amplifier including a non-inversion terminal to receive a voltage on the common electrode, an inversion terminal connected to the first node, and an output terminal to output an output voltage to the common electrode to remove the induction voltage induced to the common electrode; and

a second resistor connected between the output terminal of the operational amplifier and the first node.

8. The display device of claim 7, wherein an output voltage of the differential circuit is determined based according to the equation

9. The display device of claim 1, further comprising:

a data driver to supply a video data voltage to data lines of the display panel;

a gate driver to supply a gate pulse voltage synchronized with the data voltage to gate lines of the display panel; and

a timing controller to generate timing control signals to control operational timing of the data driver and the gate driver.

10. The display device of claim 4, further comprising:

a touch controller to generate a plurality of scanning control signals for controlling the first and second conductive pattern driving portions, and to supply the plurality of scanning control signals to the first and second conductive pattern driving portions; and

a touch perceiving processor connected to the first and second conductive patterns to compare a first capacitance of each of the first and second conductive patterns when a touch is not performed with a second capacitance when a touch is performed whenever the pulse voltage is supplied to the first and second conductive patterns, and to output a touch perceiving signal indicating whether or not a touch is performed to the touch controller.

11. The display device of claim 4, wherein the power source circuitry supplies the voltage pulse to the common voltage feedback circuit directly, or supplies the pulse voltage to the common voltage feedback circuitry through any one of the first and second conductive pattern driving portions.