Sensing circuit and sensing method of capacitive touch panel

Abstract

The invention discloses a sensing circuit and a sensing method of a (projective) capacitive touch panel. The sensing circuit comprises a reference voltage generating unit, a sensing voltage generating unit and an integral judgment unit, wherein the reference voltage generating unit comprises a preinstalled reference capacitor, and is configured to charge the preinstalled reference capacitor so as to generate a reference voltage; the sensing voltage generating unit is configured to charge at least one sensing capacitor in the (projective) capacitive touch panel so as to generate a sensing voltage; and the integral judgment unit is used to receive and judge whether boosting speeds of the reference voltage and the sensing voltage are identical so as to output a sensing voltage value.

Description

technical field [0001] The present invention relates to the field of sensing technology, in particular to a sensing circuit of a projected capacitive touch panel and a sensing method thereof. Background technique [0002] The working principle of the projected capacitive touch panel is mainly to detect the capacitance change caused by the electrostatic capacitance of the finger to the inductive capacitance formed between the XY electrodes in the projected capacitive touch panel. Common positioning (sensing) methods for projected capacitive touch panels include self-capacitance (or self-inductance) and mutual-capacitance (mutual-inductance). Taking the self-capacitance positioning (sensing) method as an example, multiple sensing circuits in two directions (XY axes) will be connected to each XY electrode, and which X electrodes and Y electrodes are detected by these sensing circuits. Capacitance changes can be used to know the user's single or multiple touch points on the pro...

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Problems solved by technology

[0003] At present, the implementation structure of the sensing circuit of the self-capacitance positioning (sensing) method is not unified, but in order not to affect the power durability of the (handheld) electronic products used in the projected capacitive touch panel when it is in standby, so How to design a self-inductance (capacitance) sensing circuit with low circuit complexity and low power consumption for application in a projected capacitive touch panel is one of the subjects that the technicians / developers in the field related to the present invention are working hard on.

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