Capacitive touch system and data transmission method in a capacitive touch system
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.
1. A data transmission method in a capacitive touch system, comprising:
using at least two first integrated circuits defining slave 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 to determine a plurality of scanned sensed values, the data transmission method comprising:
for each of the first integrated circuits, determining a touch area from the plurality of scanned sensed values including a plurality of traces having non-zero sensed touch values defining a touch position, each of the plurality of traces having non-zero sensed touch values being given an order number and sending the order number of a first trace of the plurality of traces having a non-zero sensed touch value and the order number of a last trace of the plurality of traces having a non-zero sensed touch value to a second integrated circuit defining a master integrated circuit; and
sending the sensed touch values of all traces whose order numbers range from the order number of the first trace having a non-zero sensed touch value and the order number of the last trace having a non-zero sensed touch value to the second integrated circuit.
2. A capacitive touch system, comprising:
a touch panel having a plurality of traces;
at least two first integrated circuits defining slave integrated circuits, each connected to a respective portion of the traces, the two first integrated circuits simultaneously scanning thereto to determine a plurality of scanned sensed values; and
a second integrated circuit defining a master integrated circuit connected to each of the first integrated circuits, receiving non-zero sensed touch values of the traces defining a touch position from the plurality of scanned sensed values from the first integrated circuits and calculating therewith, each of the non-zero sensed touch values being given an order number;
wherein the received non-zero sensed touch values are packaged with a data structure including:
a first field for the order number of a first trace having a non-zero sensed touch value and the order number of the last trace having a non-zero sensed touch value; and
a second field following the first field for the sensed touch values of all the traces whose order number range from the order number of the first trace having a non-zero sensed touch 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.