Electromagnetic touch device

Abstract

The invention relates to an electromagnetic touch device. The electromagnetic touch device comprises an antenna module and a control system, wherein the antenna module comprises a signal transmitting circuit and signal receiving antennae; the control system is connected with the antenna module and comprises signal amplifying circuits, a filter circuit, a detection and integral circuit, a Schmidt trigger circuit and a data processing and communication module, wherein the filter circuit is connected with the signal amplifying circuits, performs filtering processing on an amplified signal and outputs two signals; two signal receiving antennae are provided, and each signal receiving antenna is provided with a signal amplifying circuit; and the filter circuit is an addition and subtraction comparison filter circuit which simultaneously performs the filtering processing on the touch signals which are received by the two signal receiving antennae and are amplified. The electromagnetic touch device can be matched with a passive electromagnetic stylus and can also be matched with an active electromagnetic stylus by arranging the signal transmitting circuit and the two signal receiving antennae on the electromagnetic touch device at the same time and matching the addition and subtraction comparison filter circuit.

Description

technical field [0001] The present invention relates to the technical field of touch control, in particular to an electromagnetic touch device. Background technique [0002] Touch control technology is more and more applied in the field of electronic products. At present, the mainstream touch screen technologies mainly include the following types: resistive, capacitive and inductive. Among them, the inductive touch screen can be divided into active and passive according to the working principle, and the active and passive are mainly for the electromagnetic stylus. [0003] Active electromagnetic touch devices can be called active electromagnetic touch devices. Its working principle is: the electromagnetic stylus actively emits electromagnetic signals, the antenna board receives the signals and transmits them to the control system, and then the control system amplifies and filters the signals After being processed by the MCU of the control system, the touch information is s...

AI Technical Summary

Problems solved by technology

[0005] In actual use, it is found that the active electromagnetic touch device is sensitive to large-scale inductive touch applications, and the pen pressure is easier to achieve, but there is trouble in the use of the active electromagnetic stylus. Battery replacement or charging

The passive electromagnetic stylus is susceptible to interference on the main control board due to the signal-to-noise ratio factor

Existing electromagnetic touch devices use low-pass and high-pass filters composed of traditional RC circuits. The principle of this traditional RC circuit filter is to attenuate the signal. Low-pass filters attenuate more in high-frequency bands, and high-pass filters in The low-frequency band attenuates more, and the useful signal will also attenuate part of the attenuation process, especially in harsh environments where the interference signal frequency band is similar to the electromagnetic stylus emission signal frequency band, it is difficult to pass high-pass and low-pass filtering. get a better signal-to-noise ratio

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