Touch detection device and method of detecting touch

Patent metadata

Field	Value
Publication number	US-2019102034-A1
Application number	US-201815974953-A
Country	US
Kind code	A1
Filing date	May 9, 2018
Priority date	Sep 29, 2017
Publication date	Apr 4, 2019
Grant date	—

Abstract

A touch detection device and a method of detecting a touch employ: a current-to-voltage converter configured to convert a reception signal received from a touch panel into a sensing signal, and further configured to be periodically reset for a first time period in response to a reset signal; a digital-to-analog converter configured to convert an analog signal based on the sensing signal into a first digital output signal, and a controller configured to generate a second digital output signal based on the first digital output signal by performing data interpolation on a first portion of the first digital output signal corresponding to the first time period.

First claim

1 . A touch detection device, comprising:
a current-to-voltage converter configured to convert a reception signal received from a touch panel into a sensing signal, and further configured to be periodically reset for a first time period in response to a reset signal; an analog-to-digital converter configured to convert an analog signal, generated based on the sensing signal, into a first digital output signal; and a controller configured to generate a second digital output signal based on the first digital output signal by performing data interpolation on a first portion of the first digital output signal, where the first portion of the first digital output signal corresponds to the first time period.

2 . The touch detection device of claim 1 , wherein the current-to-voltage converter is configured to output a voltage having a level independent of the reception signal for the first time period, in response to the reset signal.

3 . The touch detection device of claim 1 , further comprising:
a frequency modulator configured to generate a frequency-modulated signal by downconverting a frequency of the sensing signal; a filter configured to output as a filter output signal a low frequency band of the frequency-modulated signal based on a set pass band; and an amplifier configured to generate the analog signal by amplifying, with a set gain, the filter output signal.

4 . (canceled)

5 . The touch detection device of claim 3 , wherein the frequency modulator is configured to generate the frequency-modulated signal by heterodyning a frequency of the sensing signal based on a set modulation frequency,
wherein the controller is configured to detect a frequency of the second digital output signal and is further configured to change a modulation frequency of the frequency modulator based on the frequency of the second digital output signal and the set pass band.

6 . The touch detection device of claim 3 , wherein the amplifier is configured to be periodically reset for the first time period in response to the reset signal.

7 . The touch detection device of claim 1 , wherein the controller is configured to generate the reset signal based on a timing signal provided from a display driving circuit that drives a display panel adjacent to the touch panel.

8 . The touch detection device of claim 7 , wherein the timing signal comprises a horizontal synchronizing signal indicating a timing at which the display driving circuit updates pixels of the display panel with new pixel data.

9 . (canceled)

10 . The touch detection device of claim 7 , wherein the reset signal has an active period which is earlier or later than an active period of the timing signal.

11 . The touch detection device of claim 1 , wherein the controller is configured to analyze a noise component of the first digital output signal to thereby determine a period in which noise is in the reception signal and is further configured to generate the reset signal having an active level in the period in which the noise is in the reception signal.

12 . The touch detection device of claim 1 , wherein the controller is configured to detect a magnitude and frequency of the second digital output signal and is further configured to detect touch coordinates and touch pressure generated on the touch panel based on the magnitude and frequency of the second digital output signal.

13 . The touch detection device of claim 1 , wherein the controller is configured to perform the data interpolation based on a first data value and a second data value respectively corresponding to a first point in time and a second point in time which are adjacent to the first portion of the first digital output signal.

14 . A touch detection device for processing a reception signal that varies with a touch of a pointer on a touch panel, the touch detection device comprising:
an analog front end configured to generate a first output signal by converting and amplifying the reception signal, wherein the analog front end is periodically reset in response to a reset signal to generate the first output signal having non-continuous data values; and a controller configured to generate a second output signal having continuous data values by interpolating a non-continuous period of the first output signal having the non-continuous data values, based on data values of a continuous period, and further configured to detect a frequency of the second output signal.

15 . The touch detection device of claim 14 , wherein the controller is configured to generate the reset signal based on a timing signal indicating a timing for updating pixels of a display panel adjacent to the touch panel in units of lines.

16 . The touch detection device of claim 14 , wherein the analog front end comprises:
an input buffer configured to convert the reception signal into a sensing signal; a frequency modulator configured to generate a frequency-modulated signal by downconverting a frequency of the sensing signal; a filter configured to filter a frequency component of the frequency-modulated signal based on a set pass band and to output a filter output signal; and an amplifier configured to generate an analog output signal by amplifying the filter output signal, wherein at least one of the input buffer, the frequency modulator, the filter, and the amplifier is reset in response to the reset signal.

17 . The touch detection device of claim 16 , wherein a frequency of the reception signal varies with touch pressure of the pointer, and the controller is configured to calculate the touch pressure of the pointer based on the frequency of the second output signal.

18 - 20 . (canceled)

21 . A method of detecting a touch by processing a reception signal that varies with a touch of a pointer on a touch panel, the method comprising:
generating an output signal, based on the reception signal, wherein the output signal has data values corresponding to a variation of the reception signal; generating a reconstructed output signal by interpolating at least one data value of a second period of the output signal, between a first period of the output signal and a third period of the output signal, based on a data value of the first period and a data value of the third period; and detecting a magnitude and frequency of the reconstructed output signal.

22 . The method of claim 21 , wherein the generating of the output signal comprises processing by an analog front end the reception signal to thereby generate the output signal, wherein the analog front end stops an operation during a reset period in response to a reset signal to thereby generate the output signal having non-continuous data values in the second period corresponding to the reset period.

23 . The method of claim 22 , wherein the reset signal is generated based on a horizontal synchronizing signal indicating a timing for updating pixels of a display panel adjacent to the touch panel.

24 . The method of claim 21 , wherein the generating of the output signal comprises:
converting the reception signal into a sensing signal; generating a low frequency signal by down-modulating a frequency of the sensing signal; filtering noise of the low frequency signal to output a noise-filtered low frequency signal; generating an analog signal by amplifying the noise-filtered low frequency signal; and generating the output signal by converting the analog signal into a digital signal.

25 . The method of claim 24 ,

Assignees

• Samsung Electronics Co Ltd

Inventors

• Nam Sang-Pil
• Lee Kyung-Hoon
• Choi Michael

Classifications

• G06F3/03547

  Touch pads, in which fingers can move on a surface · CPC title

• G06F3/0414

  using force sensing means to determine a position · CPC title

• G09G2310/0264

  Details of driving circuits · CPC title

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/044

  by capacitive means · CPC title