Anti-noise method of capacitive touch screen and touch control chip

Abstract

The invention provides an anti-noise method of a capacitive touch screen and a touch control chip. The anti-noise method comprises the following steps that: a noise environment is detected periodically; on the basis of determination, when existence of an impulse noise is detected in the noise environment during the last detection period and the frequency of the impulse noise is larger than or equal to a preset frequency threshold value, non-linear filtering processing is carried out a touch screen signal during the current detection period; and when no impulse noise exists in the noise environment during the detection of the last detection period or the existence of the impulse noise is detected but the frequency of the impulse noise is less than the presser frequency threshold value, linear filtering processing is carried out on the touch screen signal during the current detection period. Meanwhile, a method for switching a driving frequency of the capacitive touch screen into an unoccupied frequency under the linear filtering is also provided. According to the technical scheme, interferences on the capacitive touch screen by various noises can be effectively inhibited.

Description

technical field [0001] Embodiments of the present invention relate to touch screen technology, and in particular to a capacitive touch screen anti-noise method and a touch chip. Background technique [0002] Capacitive touch screens are widely used in portable devices, such as mobile phones, tablet computers, etc. The capacitive touch screen is essentially a system that uses the principle of capacitance measurement to work. The common capacitance measurement method in the industry is mainly based on the measurement method of sending signal-receiving signal. Part of the noise components within the operating frequency band of the capacitive touch screen will cause serious co-frequency interference, affect the accuracy of the capacitive touch screen to the contact, and even cause false alarms, seriously affecting the normal operation of the capacitive touch screen. [0003] In the existing anti-noise technical solutions, most of the solutions are to avoid the interference of n...

AI Technical Summary

Problems solved by technology

A part of the noise component in the working frequency band of the capacitive touch screen will cause serious same-frequency interference, affect the accuracy of the capacitive touch screen to the contact, and even cause false alarms, seriously affecting the normal operation of the capacitive touch screen

[0003] In the existing anti-noise technical solutions, most of the solutions are to avoid the interference of noise on the TP chip from the external environment. The scanning frequency of the capacitive touch screen is set to this frequency area to achieve the purpose of controlling interference, but if there is interference in the full frequency band, this solution will not be applicable

It can be seen that the existing technical solutions cannot well solve the interference to the capacitive touch screen such as colored noise and impulse noise.

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