Anti-noise method and device of touch screen

Abstract

The invention provides a touch screen data processing method for inhibiting noise and a touch screen control device which applies the method. The method comprises the following steps: (1) receiving an analog signal of a touch screen, and sampling the analog signal of the touch screen to obtain a digital signal; (2) according to a sampling value, calculating a reference value corresponding to the sampling point; (3) comparing the sampling value and the corresponding reference value to obtain a deviation, and comparing the deviation with a preset threshold value; (4) if the deviation is smaller than the threshold value, keeping the sampling value, abandoning the sampling value if the deviation is greater than the threshold value, and replacing the sampling value with the corresponding reference value obtained by the calculation; and (5) applying the data obtained in the step (4) to touch information processing, and calculating a touch position. The method can effectively inhibit common-mode noise and improve the detection precision of a touch position. Compared with a traditional noise elimination method, the touch screen data processing method has the following outstanding advantages of being simple in calculation method, small in hardware resource occupation when a touch signal is realized and high in processing speed, is not affected by the length of a scanning signal and can calculate the signals of any length.

Description

technical field [0001] The invention relates to the field of touch screens, in particular to a touch screen data processing method for anti-noise and a touch screen control device. Background technique [0002] Touch screens are widely used in portable devices, such as mobile phones, tablet computers and so on. When the touch screen control device is working, it is susceptible to interference from various noise sources, and typical noises include common-mode noise from charging equipment or display equipment. In touch screen data processing systems, common mode noise is an important factor affecting system performance. With the miniaturization and portability of charging equipment, its noise interference is becoming more and more serious. Strong common-mode noise will obviously affect the response speed and accuracy of the system to touch control, and in severe cases, it will cause false alarms of the position, make the touch control invalid, and seriously affect the norma...

AI Technical Summary

Problems solved by technology

When interfered by common mode noise, the signal obtained on the sensing layer of the touch screen is no longer a single sine or cosine signal, but a sampling signal including jitter, such as Figure 2b As shown, the signal cannot accurately restore the touch information to be detected after demodulation

[0005] Existing noise elimination schemes include setting digital filters implemented by hardware circuits to process coordinate data. The filtering principles are traditional weighted average, median algorithm, arithmetic mean algorithm, etc. Simple digital filtering cannot The suppression of interference caused by common mode noise

In addition, the Chinese published patent CN1503118A also proposes a method of using a clock circuit to control received data to reduce noise. This method is costly to implement and has a complex structure

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