Driving frequency selection method for capacitive multipoint touch system

Abstract

The invention provides a driving frequency selection method for a capacitive multipoint touch system. The capacitive multipoint touch system in an idle mode randomly selects operating frequency and detects whether touch points exist or not by means of self-inductance capacitor driving sensing technology. When touch points exist, the capacitive multipoint touch system is switched into an operating mode and detects the touch point positions to judge whether noise interference exists or not by means of mutual-inductance capacitor driving sensing technology. When noise exists, the capacitive multipoint touch system is switched into the idle mode and finds out image unprocessed data of a self-inductance capacitor lowest in noise through stimulus waves of multiple driving frequencies, the driving frequency corresponding to the self-inductance capacitor lowest in noise is set as the operating driving frequency of a mutual-inductance capacitor, then the system is switched into the operating mode, processing data volume can be reduced by means of the mutual-inductance capacitor driving sensing technology, and power consumption can be further reduced.

Description

Technical field [0001] The present invention relates to the technical field of touch panels, and in particular to a method for selecting a driving frequency of a capacitive multi-touch system. Background technique [0002] The technical principle of the touch panel is that when a finger or other medium touches the screen, it detects voltage, current, sound waves or infrared rays according to different sensing methods, and then measures the coordinate position of the touch point. For example, the resistive touch panel uses the potential difference between the upper and lower electrodes to calculate the position of the pressure point to detect the touch point. The capacitive touch panel uses the capacitance change generated by the electrostatic combination between the arranged transparent electrodes and the human body to detect its coordinates from the generated current or voltage. [0003] According to the principle of capacitive touch technology, it can be divided into two technol...

AI Technical Summary

Problems solved by technology

[0011] (1), when there are floating conductors (such as water droplets, oil stains, etc.) on the touch panel, it is easy to cause misjudgment of the touch point; and

[0012] (2) When there are multiple touch points on the touch panel at the same time, there will be a phenomenon of ghosting, resulting in the self-inductance capacitive sensing method, which is difficult to support multi-touch applications

At the same time, due to the large amount of data, the time required to convert the sensing signal from an analog signal to a digital signal is increased a lot; and

[0020] (3) Due to the large amount of data, the power consumption of data processing will also increase accordingly

However, the prior art clearly needs to obtain three sets of touch images, that is, it needs three times the power and time, and needs to process three sets of touch images.

Therefore, there is still room for improvement in the drive frequency selection technology of the existing capacitive touch panel

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