Touch screen controller

Patent metadata

Field	Value
Publication number	US-2019018538-A1
Application number	US-201816131891-A
Country	US
Kind code	A1
Filing date	Sep 14, 2018
Priority date	Jan 8, 2016
Publication date	Jan 17, 2019
Grant date	—

Abstract

A touch screen controller includes a driving circuit adapted for transmitting a high working voltage signal to the touch screen for enabling the touch screen to couple the high working voltage signal and to further generate a low working voltage signal, and a sensing circuit adapted for receiving the low working voltage signal from the touch screen for matching with the high working voltage signal to determine the variation in signal voltage between the high working voltage signal and the low working voltage signal and to further recognize a touch on the touch screen. The voltage level of the high working voltage signal provided by the driving circuit is five times over the voltage level of the low working voltage signal so that the sensing circuit can get the best signal-to-noise ratio, achieving optimal performance in touch control recognition.

First claim

What the invention claimed is:

1 . A controller used in a touch screen, comprising:
a driving circuit adapted for transmitting a high working voltage signal to said touch screen for enabling said touch screen to couple said high working voltage signal and to further generate a low working voltage signal output when a touch on said touch screen; and a sensing circuit adapted for transmitting a working voltage to said touch screen for receiving said low working voltage signal from said touch screen for matching with said high working voltage signal to determine the variation in signal voltage between said high working voltage signal and said low working voltage signal and to further recognize a touch on said touch screen; wherein the voltage level of said high working voltage signal provided by said driving circuit is five times over said working voltage provided by said sensing circuit and the voltage level of said low working voltage signal is equal to or smaller than said working voltage.

2 . The controller as claimed in claim 1 , wherein said driving circuit comprises a digital-to-analog converter, a signal amplifier circuit, a signal selector switch and at least one high load voltage electrostatic discharge protection circuit, said digital-to-analog converter being adapted to receive a waveform control signal and to convert said waveform control signal into a digital signal, and then to transmit said digital signal to said signal amplifier circuit for amplification, said signal amplifier circuit being adapted to amplify said digital signal and then to transmit the amplified said digital signal to said signal selector switch for transmission to said touch screen through one of said at least one high load voltage electrostatic discharge protection circuit.

3 . The controller as claimed in claim 1 , wherein said driving circuit comprises at least one driving signal circuit, each said driving signal circuit comprising a voltage level shifter, a complementary metal oxide semiconductor transistor and a high load voltage electrostatic discharge protection circuit, said voltage level shifter being adapted to receive a low load voltage signal and to boost said low load voltage signal into a high load voltage signal and then to transmit said high load voltage signal to the associating said complementary metal oxide semiconductor transistor, enabling the associating said complementary metal oxide semiconductor transistor to transmit said high load voltage signal through the associating said high load voltage electrostatic discharge protection circuit to said touch screen.

4 . The controller as claimed in claim 1 , wherein said controller further comprises a chip core, a low load voltage electrostatic discharge protection circuit and a resistor, said resistor having one end thereof electrically connected to said touch screen and an opposite end thereof electrically connected to one end of said sensing circuit, said sensing circuit having an opposite end thereof electrically connected to one end of said low load voltage electrostatic discharge protection circuit, said low load voltage electrostatic discharge protection circuit having an opposite end thereof electrically connected to said chip core.

5 . The controller as claimed in claim 1 , wherein said controller further comprises a chip core, a low load voltage electrostatic discharge protection circuit and a resistor, said sensing circuit having one end thereof electrically connected to said touch screen and an opposite end thereof electrically connected to one end of said resistor, said resistor having an opposite end thereof electrically connected to one end of said low load voltage electrostatic discharge protection circuit, said low load voltage electrostatic discharge protection circuit having an opposite end thereof electrically connected to said chip core.

6 . The controller as claimed in claim 1 , wherein said controller further comprises a chip core, a first low load voltage electrostatic discharge protection circuit electrically connected to said chip core, a second low load voltage electrostatic discharge protection circuit electrically connected to said touch screen through said sensing circuit, and a resistor electrically connected in series between said first low load voltage electrostatic discharge protection circuit and said second low load voltage electrostatic discharge protection circuit.

7 . The controller as claimed in claim 1 , wherein said driving circuit is electrically connected to an external power source of voltage equal to or greater than 18 volts; said sensing circuit is electrically connected to an external power source of voltage equal to or smaller than 3.3 volts.

Assignees

• Egalax_Empia Tech Inc

Inventors

• Lin Po-Chuan

Classifications

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/044

  by capacitive means · CPC title

• G06F3/04164

  Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads · CPC title