CIRCUIT FOR PROCESSING TOUCH LINE SIGNAL OF TOUCH SCREEN

• US 20110279407A1
• Filed: 05/11/2011
• Published: 11/17/2011
• Est. Priority Date: 05/13/2010
• Status: Abandoned Application

• Current Assignee: Silicon Works Co., Ltd.
• Original Assignee: Silicon Works Co., Ltd.
• Inventors: Lee, Sang-Gug, Jang, Yeong-Shin, Na, Joon-Ho, Kim, Young-Bok, KIM, Ji-Hun
• Application Number:
  US13/105,301
• Publication Number:
  US 20110279407A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A circuit for processing a touch line signal of a touch screen includes a plurality of sensing read circuits and a switch unit. The plurality of sensing read circuits include sensing read-out units and integrators, respectively. The sensing read-out units are configured to precharge a first sensor capacitor and a second sensor capacitor formed on a touch screen panel with a ground voltage and a supply voltage, allow charges charged in the first sensor capacitor and the second sensor capacitor to be shared, and read-out a charge sharing result obtained by allowing the charges of the first sensor capacitor and the second sensor capacitor to be shared. The integrators are configured to integrate output voltages of the sensing read-out units. The switch unit is configured to sequentially connect output terminals of the plurality of sensing read circuits to an input terminal of an analog-to-digital converter.

Claims

1. A circuit for processing a touch line signal of a touch screen comprising:

a plurality of sensing read circuits including sensing read-out units, which are configured to precharge a first sensor capacitor and a second sensor capacitor formed on a touch screen panel with a ground voltage and a supply voltage, allow charges charged in the first sensor capacitor and the second sensor capacitor to be shared, and read-out a charge sharing result obtained by allowing the charges of the first sensor capacitor and the second sensor capacitor to be shared, and integrators configured to integrate output voltages of the sensing read-out units; and

a switch unit configured to sequentially connect output terminals of the plurality of sensing read circuits to an input terminal of an analog-to-digital converter.

2. The circuit according to claim 1, wherein the first sensor capacitor and the second sensor capacitor are formed on touch lines adjacent to each other on the touch screen panel.

3. The circuit according to claim 1, wherein each sensing read-out unit comprises:

a first precharge switch configured to precharge the first sensor capacitor with the ground voltage;

a second precharge switch configured to precharge the second sensor capacitor with the supply voltage;

a charge sharing switch configured to allow the charges charged in the precharged first sensor capacitor and the precharged second sensor capacitor to be shared; and

a read-out switch configured to read out the charge sharing result.

4. The circuit according to claim 3, wherein the first precharge switch has a first terminal connected to a ground voltage and a second terminal connected to one terminal of the first sensor capacitor, and the second precharge switch has a first terminal connected to a supply voltage and a second terminal connected to one terminal of the second sensor capacitor.

5. The circuit according to claim 3, wherein the charge sharing switch has a first terminal connected to a second terminal of the first precharge switch and a second terminal connected to a second terminal of the second precharge switch.

6. The circuit according to claim 3, wherein the read-out switch has a first terminal connected to a common node between the first sensor capacitor and the second sensor capacitor and a second terminal connected to an input terminal of the integrator.

7. The circuit according to claim 1, wherein the integrator is configured to output one of a first level voltage, a second level voltage, and a preset voltage between the first level voltage and the second level voltage according to whether the first sensor capacitor and the second sensor capacitor are touched.

8. The circuit according to claim 7, wherein the preset voltage is a reference voltage.