Elan Microelectronics Corporation

Jung-Shou Huang

Tse-Lun Hung

Chia-Mu Wu

Hsin-Shieh Tsai

Shun-Yi Chen

Yi-Chia Hsu

Chang-Hsin Chen

Tung-Ming Yang

High noise immunity sensing methods and apparatus are provided for a capacitive touch device, which sense the capacitive touch device for self capacitance or mutual capacitance or both with different scan frequencies in a frame, to thereby suppress certain frequency noise interference. By combining time domain and space domain noise-eliminating approaches, probabilities of noise interference are reduced, without compromising other parameters.

High noise immunity sensing methods and apparatus for a capacitive touch device

A sensing method and a sensing apparatus for a capacitive touch device sense variations of self capacitances of first traces in a first direction and second traces in a second direction and variations of mutual capacitances of intersections between the first traces and the second traces, and then generates fourth sensed values from the first, second and third sensed values to serve as sensed values of the changes of the mutual capacitances of the intersections between the first traces and the second traces for identifying one or more touch points. Therefore, noise interference is suppressed and real touch points can be easily to be identified.

A scan method for a touch panel has steps of: receiving a self-sensing frame; calculating sensing slopes between each sensing line and its neighboring sensing lines in the self-sensing frame; determining whether any sensing slope is larger than a slope threshold, and marking the sensing line if the sensing slope is larger than the slope threshold; and executing a mutual scan approach on the marked sensing lines to produce a mutual sensing frame without sensing point caused by noise. Further, the present invention also increases the frame rate since only a part of sensing lines need to be scanned.

Scan method for a touch panel

A capacitive touch system uses two or more integrated circuits to simultaneously scan a touch panel in such a manner that each of the integrated circuits scans only a portion of the touch panel to retrieve a respective detected data by itself. All the detected data are used for computation by one of the integrated circuits or one other than the integrated circuits to determine a touch information. This approach enables axis intersect projected capacitance touch integrated circuits applicable to a large scale touch panel, without degrading the frame rate of a capacitive touch system.

Capacitive touch system and control method for a capacitive touch system

A method of detecting floating mode of a touch panel has steps of reading a sensing cluster and presetting a detection window; taking each sensing point of the sensing cluster as a center point of the detection window; after determining that the center point has a negative sensing value qualifying to be generated under a floating mode, further determining a count of the sensing points other than the center point having the sensing values generated under a grounding mode and incrementing an accumulative number by one if the count exceeds a first critical value; keeping incrementing the accumulative number until each sensing point in the sensing cluster has been taken as the center point of the detection window for scanning; and determining if the accumulative number exceeds a second critical value, and if positive, further determining that the current sensing cluster is generated under the floating mode.

Method of detecting floating mode of a touch panel

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.

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

A capacitive touch system includes a touch panel and two touch integrated circuits connected to the touch panel to scan thereto. The touch panel has a boundary trace connected to both of the two touch integrated circuits. When one of the two touch integrated circuits charges/discharges the boundary trace, the other touch integrated circuit does not charges/discharges the boundary trace.

Capacitive touch system and sensing method for a capacitive touch system

A capacitive touch system uses at least two touch integrated circuits to simultaneously scan a touch panel, each of the touch integrated circuits only for scanning a portion of the traces 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. Sensing methods are provided to determine a sensed value for a boundary trace which is the last one of the traces connected to a first touch integrated circuit and prior to the first one of the traces connected to a second touch integrated circuit.

Sensing method for a capacitive touch system

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.

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Da-an Shiang, Taiwan

Jung-Shou Huang