Capacitive touch system and data transmission method in a capacitive touch system

• US 20090250269A1
• Filed: 03/31/2009
• Published: 10/08/2009
• Est. Priority Date: 04/02/2008
• Status: Active Grant

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Hung, Tse-Lun, Chen, Chang-Hsin, Huang, Jung-Shou
• Granted Patent: US 8,592,698 B2
• Time in Patent Office: Days
• US Class Current: 178/18.60
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 to retrieve the sensed data from its responsible traces. Therefore, the capacitive touch system can maintain a good frame rate, even the touch panel is a large scale touch panel. A data transmission method transmits only the non-zero sensed values to a second integrated circuit where a calculation with the non-zero sensed values is executed, and thereby reduces the data transmission time.

Claims

1. A data transmission method in a capacitive touch system using at least two first integrated circuits to simultaneously scan a touch panel, each of the first integrated circuits for scanning a respective portion of a plurality of traces of the touch panel, each of the traces being given an order number, the data transmission method comprising:

for each of the first integrated circuits, sending the order number of a first trace having a non-zero sensed value and the order number of a last trace having a non-zero sensed value to a second integrated circuit; and

sending the sensed values of all traces whose order numbers range from the order number of the first trace having a non-zero sensed value and the order number of the last trace having a non-zero sensed value to the second integrated circuit.

2. A capacitive touch system, comprising:

a touch panel having a plurality of traces, each of the traces being given an order number;

at least two first integrated circuits, each connected to a respective portion of the traces for scanning thereto; and

a second integrated circuit connected to each of the first integrated circuits, receiving non-zero sensed values of the traces from the first integrated circuits and calculating therewith;

wherein the sent non-zero sensed values are packaged with a data structure including;

a first field for the order number of a first trace having a non-zero sensed value and the order number of the last trace having a non-zero sensed value; and

a second field following the first field for the sensed values of all the traces whose order number range from the order number of the first trace having a non-zero sensed value and the order number of the last trace having a non-zero sensed value.

3. The capacitive touch system of claim 2, wherein the second integrated circuit coordinates the overall operation of the capacitive touch system.

4. The capacitive touch system of claim 2, wherein the second integrated circuit is responsible for external communications.

5. The capacitive touch system of claim 2, wherein the second integrated circuit comprises an axes-intersecting projected capacitance touch integrated circuit.