A capacitive touch detection circuit and detection device

Abstract

The invention discloses a capacitance-type touch control detection circuit for detecting the change in a detected capacitance, which comprises a constant voltage source, a first switch, a first control circuit, a compensating module and an amplifying module, wherein the constant voltage source is used for charging a detected capacitor; the first switch is used for controlling the charging time of the detected capacitor, and the constant-voltage source, the first switch and the detected capacitor are connected in series; the first control circuit is used for controlling the on and off time of the first switch; the compensating module is used for reducing the electric quantity of the detected capacitor to a preset value; and the amplifying module is used for amplifying the voltage of the detected capacitor with reduced electric quantity. The invention also provides a detection device and a detection method. According to the invention, after the compensating module reduces the electric quantity of the detected capacitor to the preset value, the amplifying module amplifies the voltage; the reduction in the electric quantity of the detected capacitor reduces the voltage of the detected capacitor, so that the capacitance change in the detected capacitor is higher than the capacity change under a condition that the compensating module is not available; and the sensitivity of the detection circuit is increased.

Description

technical field [0001] The invention relates to the technical field of touch detection, in particular to a capacitive touch detection circuit, a detection device and a detection method thereof. Background technique [0002] Existing detection methods for capacitive touch devices include two basic schemes based on self-capacitance detection and mutual capacitance detection. change to realize the recognition operation. In general, the capacitance change caused by the proximity of the conductor to the device is much smaller than the measured capacitance of the device. These measured capacitances include the self-capacitance of the screen itself and the parasitic capacitance of the screen. Due to the existence of the capacitance to be measured, the effective detection range of the detection circuit is limited, thereby limiting the improvement of detection sensitivity for small capacitance changes. [0003] The limitation of the measured capacitance to the effective detection r...

AI Technical Summary

Problems solved by technology

[0004] The technical problem solved by the invention is that when the conductor is close to the capacitive touch device in the prior art, the capacitance change is smaller than the measured capacitance change, and the detection sensitivity is low

Images