Method for scanning projective capacitive touch panel

Abstract

The invention discloses a method for scanning a projective capacitive touch panel, which comprises the following steps of: (A) dividing all mutual capacitors into two groups according to resistance-capacitance constants to an integrator, and setting a first standard voltage value and a first variation difference of each group of mutual capacitors and a second standard voltage value and a second variation difference of each mutual capacitor respectively; (B) applying higher single-frequency excitation signals to the group of mutual capacitors with lower resistance-capacitance constants and applying lower single-frequency excitation signals to the group of mutual capacitors with higher resistance-capacitance constants to perform scanning so as to obtain first current voltage values of all the mutual capacitors in each group, and comparing the first current voltage values with the first standard voltage value corresponding to the group to judge suspicious mutual capacitors beyond the range of the first variation difference; and (C) applying low-frequency excitation signals to the suspicious mutual capacitors to obtain second current voltage values of the suspicious mutual capacitors, and comparing the second current voltage values with the second standard voltage value corresponding to the mutual capacitors to judge the mutual capacitors beyond the range of the second variation difference and affected by touch. The method is quick to scan and accurate to position.

Description

technical field [0001] The invention relates to a scanning method of a capacitive touch panel, in particular to a scanning method of a projected capacitive touch panel. Background technique [0002] At present, capacitive touch panels include projected capacitive touch panels and surface capacitive touch panels, among which projected capacitive touch panels are widely used in electronic products, such as figure 1 Shown: the structure of a known projected touch screen 1, including a protective layer 11, a substrate 12, a projected capacitive touch panel 13 and a controller 14; the protective layer 11 is a transparent material, located above the projected capacitive touch panel 13 The substrate 12 is located below the projected capacitive touch panel 13; the controller 14 is electrically connected to the projected capacitive touch panel 13 for driving the projected capacitive touch panel 13 to work, and the controller 14 includes a pulse generator , Integrator. [0003] Such...

AI Technical Summary

Problems solved by technology

In order to ensure the accuracy of positioning, traditional projected capacitive touch panels use a low single-frequency excitation signal to scan in order to obtain a stable voltage value for each mutual capacitance, but low-frequency scanning means that it takes a long time time

Therefore, scanning with a single low-frequency excitation signal is not an optimized scanning method

[0012] The present invention studies the defect that the existing projected capacitive touch panel scanning method is not suitable for scanning medium and large-sized panels, and finds out a scanning method with fast scanning speed and high scanning accuracy, which is suitable for scanning medium and large-sized panels. new method

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