Circuit complexity reduction of a capacitive touch system

• US 20090251430A1
• Filed: 03/31/2009
• Published: 10/08/2009
• Est. Priority Date: 04/02/2008
• Status: Abandoned Application

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Hung, Tse-Lun, Chen, Chang-Hsin, Huang, Jung-Shou
• Application Number:
  US12/385,096
• Publication Number:
  US 20090251430A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A capacitive touch system uses at least two first integrated circuits to simultaneously scan a touch panel, each of the first integrated circuits only for scanning a portion of the touch panel. Therefore, the capacitive touch system can maintain a good frame rate, even the touch panel is a large scale touch panel. Each of the first integrated circuits transmits its sensed data to a second integrated circuit where a calculation with the received sensed data is executed. The second integrated circuit has at least a common pin connected to each of the first integrated circuits, and therefore the number of pins of the second integrated circuit is reduced.

Claims

1. A capacitive touch system, comprising;

a touch panel;

at least two first integrated circuits connected to the touch panel, each of the first integrated circuits scanning a respective portion of the touch panel and having at least a first pin to transmit its sensed data retrieved by itself; and

a second integrated circuit having at least a second pin connected to the at least a first pin of each of the first integrated circuits to receive the sensed data therefrom, and calculating with the received sensed data.

2. The capacitive touch system of claim 1, wherein each of the first integrated circuits comprises an axis intersect projected capacitance touch integrated circuit.

3. The capacitive touch system of claim 1, wherein each of the first integrated circuits transmits its sensed data to the second integrated circuit in a serial transmission mode.

4. The capacitive touch system of claim 1, wherein each of the first integrated circuits transmits its sensed data to the second integrated circuit in a parallel transmission mode.

5. The capacitive touch system of claim 1, wherein the second integrated circuit sends out an address signal to select one from the first integrated circuits to transmit the sensed data thereof.

6. The capacitive touch system of claim 5, wherein the second integrated circuit has at least a third pin connected to each of the first integrated circuits to send the address signal thereto.

7. The capacitive touch system of claim 1, wherein the second integrated circuit sends out a selection signal to determine a data format for the sensed data to be sent from any one of the first integrated circuits.

8. The capacitive touch system of claim 1, wherein the second integrated circuit has a third pin connected to each of the first integrated circuits to send a clock thereto.

9. The capacitive touch system of claim 1, wherein the second integrated circuit is responsible for scanning a respective portion of the touch panel.