Method, device and system for detecting self-capacitance touch screen

Abstract

The embodiment of the invention discloses a method, a device and a system for detecting a self-capacitance touch screen. The method comprises the following steps of: receiving scanning waveform by a current detecting self-capacitance touch screen channel; inputting voltage of the scanning waveform to the input end of a voltage following unit, and at least driving a preset channel adjacent to the current detecting self-capacitance touch screen channel through the output end of the voltage following unit; and calculating self-capacitance touch screen coordinate data when touch happens in the current detecting channel. By the method, touch detecting interference to the current detecting channel of the touch screen due to water vapor or water drops is shielded, the relative change amount caused by the same touch is increased, and the detecting sensitivity of the self-capacitance touch screen is improved.

Description

technical field [0001] The present invention relates to the technical field of capacitive touch screen detection, and more specifically, to a self-capacitance touch screen detection method, device and system. Background technique [0002] Today, portable terminals such as mobile phones and tablet computers are widely used. As the mainstream portable terminal screen at this stage, capacitive touch screens are loved by people for their high sensitivity and smooth operation. Capacitive touch screens include surface capacitive touch screens and projected capacitive touch screens. The projected capacitive touch screens are divided into two implementations, self-capacitive and mutual-capacitive, according to detection methods. [0003] The self-capacitance detection is to judge the occurrence of a touch event by detecting the increase of the capacitance of the channel to the ground, that is, the increase of the capacitance to the ground. by figure 1 Taking the M channel in the e...

AI Technical Summary

Problems solved by technology

However, when the surface of the capacitive screen is disturbed by external humid air or water droplets during detection, the problem of inaccurate detection coordinate data will occur:

[0007] From the above analysis, it can be seen that the existing detection technology has at least the following defects: when detecting the channel of the capacitive screen, if there is water vapor or water droplets on the screen, the coordinate data of the touch cannot be accurately detected; secondly, due to the capacitance C1 ( image 3 ), or capacitors C1 and C2 in series ( Figure 4 Middle) exists, which increases the ground capacitance of the detection channel, so that the relative change of the ground capacitance caused by the same touch is small, and the detection sensitivity of the self-capacitance touch screen is reduced

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