Elan Microelectronics Corporation

Chia-Mu Wu

Jung-Shou Huang

Tse-Lun Hung

Yi-Chia Hsu

Shun-Yi Chen

Tung-Ming Yang

Min-Jhih Lin

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 passive architecture for scanning a touch panel includes a master IC and at least one passive touch IC connected to the master IC. The master IC generates a command to configure the scan parameters of the at least one passive touch IC, and the at least one passive touch IC scans the touch panel with the scan parameters in response to the command.

Passive architecture and control method for scanning a touch panel

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 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.

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Hsinchu, Taiwan

Chia-Mu Wu