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

• US 20090251428A1
• 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 8,022,940 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/044 by capacitive means

Abstract

A capacitive touch system uses at least two integrated circuits to simultaneously scan a touch panel, each scanning only a portion of traces of the touch panel, and a second integrated circuit to receive sensed data from the first integrated circuits. The sensed data contains parameters representing a sum of the sensed values of all traces in a direction that one of the first integrated circuits is in charge of scanning, a sum of products obtained by multiplying the sensed value of each trace in the direction that the one of the first integrated circuits scans by the order number of that trace, a number of fingers in the direction detected by the one of the first integrated circuits, and whether or not the sensed values of the first and last traces in the direction that the one of the first integrated circuits scans are zero.

Claims

1. A data transmission method in a capacitive touch system including at least two first integrated circuits to simultaneously scan a touch panel and a second integrated circuit to receive sensed data from the first integrated circuits, the data transmission method comprising:

selecting one of the first integrated circuits to send five parameters therefrom to the second integrated circuit;

wherein the first parameter represents a sum of the sensed values of all traces in a direction that the selected first integrated circuit is in charge of scanning, the second parameter represents a sum of products obtained by multiplying the sensed value of each trace in the direction that the selected first integrated circuit scans by the order number of that trace, the third parameter represents a number of fingers in the direction detected by the selected first integrated circuit, the fourth parameter indicates whether or not the sensed value of the first trace in the direction that the selected first integrated circuit is in charge of scanning is zero, and the five parameter indicates whether or not the sensed value of the last trace in the direction that the selected first integrated circuit is in charge of scanning is zero.

2. A capacitive touch system, comprising:

a touch panel having a plurality of traces;

at least two first integrated circuits to simultaneously scan the touch panel, each scanning only a portion of the traces; and

a second integrated circuit connected to the first integrated circuits, to receive sensed data therefrom;

wherein one of the first integrated circuits sends to the second integrated circuit a sensed data packaged with a data structure including;

a first field for notifying the second integrated circuit a sum of the sensed values of all traces in a direction that the one of the first integrated circuits is in charge of scanning;

a second field following the first field for notifying the second integrated circuit of a sum of products obtained by multiplying the sensed value of each trace in the direction that the one of the first integrated circuits by the order number of that trace;

a third field following the second field for notifying the second integrated circuit of a number of fingers in the direction detected by the one of the first integrated circuits;

a fourth field following the third field for notifying the second integrated circuit whether or not the sensed value of the first trace in the direction that the one of the first integrated circuits is in charge of scanning is zero; and

a fifth field following the fourth field for notifying the second integrated circuit whether or not the sensed value of the last trace in the direction that the one of the first integrated circuits is in charge of scanning is zero.

3. The capacitive touch system of claim 2, wherein the second integrated circuit calculates with the received sensed data to determine the central point and the number of the fingers in the direction.

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

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

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