Multichannel touch controller having a standby channel switching circuit

Patent metadata

Field	Value
Publication number	US-2018188879-A1
Application number	US-201715614953-A
Country	US
Kind code	A1
Filing date	Jun 6, 2017
Priority date	Dec 30, 2016
Publication date	Jul 5, 2018
Grant date	—

Abstract

A multichannel touch controller includes a signal receiving circuit having N electrode pins electrically connected to touch screen for receiving respective sensing signals, switching circuit having N switch sets each consisting of first switch and second switch respectively connected in parallel to the N electrode pins, microcontroller, and processing unit having N analog front-end circuits and analog-to-digital converters with N analog front-end circuits respectively electrically connected to the first switches, the 2 nd analog front-end circuit and the N+1 analog front-end circuits respectively electrically connected to the second switches and the analog-to-digital converters respectively electrically connecting the analog front-end circuits to the microcontroller (MCU) to constitute N+1 channels for processing sensing signals so that when one channel fails, the microcontroller switches off the respective first switch and switches on the respective second switch so as to skip the failed channel until switching of the last electrode pin to the standby channel.

First claim

What the invention claimed is:

1 . A multichannel touch controller used in a touch screen, comprising:
a signal receiving circuit of a controller comprising N electrode pins electrically connected to a touch screen for receiving respective sensing signals generated by said touch screen; a switching circuit electrically connected to said N electrode pins, comprising N switch sets each consisting of a first switch and a second switch, said first switches and said second switches of said N switch sets of said switching circuit being respectively connected in parallel to said N electrode pins of said signal receiving circuit; a microcontroller; and a processing unit comprising N analog front-end circuits and analog-to-digital converters, the said N analog front-end circuits being respectively electrically connected to said first switches of the multiple said switch sets of said switching circuit, said 2 nd analog front-end circuit and said N+1 analog front-end circuits being respectively electrically connected to the said second switches of the multiple said switch sets of said switching circuit, said analog-to-digital converters respectively electrically connecting the said analog front-end circuits to said microcontroller (MCU) to constitute N+1 channels for processing sensing signals; and wherein when one said channel is damaged, said microcontroller switches off the respective said first switch and switches on the respective said second switch so as to skip the said damaged channel until switching of the last said electrode pin to the said channel in standby.

2 . The multichannel touch controller as claimed in claim 1 , wherein the said first switches and said second switches of the multiple said switch sets of said switching circuit have respective input ends thereof respectively connected in parallel to said N electrode pins through respective common input contacts; said N analog front-end circuits of said processing unit are respectively electrically connected to respective output ends of said first switches of the multiple said switch sets of said switching circuit; said second switches of the multiple said switch sets of said 2 nd switching circuit are respectively electrically connected to said 2 nd analog front-end circuit and said N+1 analog front-end circuit of said processing unit through a respective output contact.

3 . The multichannel touch controller as claimed in claim 1 , wherein the said first switches and said second switches of the multiple said switch sets of said switching circuit are selected from the group of single-pole single-throw (SPST) toggle switches, transistor switches and diode switches, and respectively switchable between an ON position and an OFF position by a switching signal provided by said microcontroller.

4 . The multichannel touch controller as claimed in claim 1 , further comprising a test signal generating circuit mounted in said controller, said test signal generating circuit comprising n+1 third switches, a plurality of common input contacts respectively electrically coupled to respective input ends of said third switches, and a plurality of output contacts respectively electrically connecting respective output ends of said third switch to the respective said channels between the respective said first switches of said switching circuit and the respective said analog front-end circuits of said processing unit.

5 . The multichannel touch controller as claimed in claim 4 , wherein a microcontroller is capable of controlling said test signal generating circuit to test the functioning of said channels subject to the steps of:
(a1) said microcontroller enabling switching signals SWt to switch on the respective said third switches of said test signal generating circuit, enabling said test signal generating circuit to transmit a test signal through each said third switch to test each said channel; (a2) said microcontroller judging each said channel to be normal or abnormal according to the rest result, and then proceeding to step (a3) if all said channels are normal, or step (a4) if one said channel failed; (a3) said microcontroller enabling all switching signals SWa to switch on all the said first switches of said switching circuit; (a4) said m th channel failed, said microcontroller proceeding to step (a5); and (a5) said microcontroller enabling m−1˜0 switching signal SWa to switch on the respective said first switches and N˜m switching signals SWb to switch on the respective second switches sequentially so as to skip the defective said m th channel until switching of the last said electrode pin to the said standby channel.

6 . The multichannel touch controller as claimed in claim 4 , wherein said first switches and said second switches of said switching circuit and said third switches of said test signal generating circuit are selected from the group of single-pole single-throw (SPST) toggle switches, transistor switches and diode switches, and respectively switchable between an ON position and an OFF position by a switching signal provided by said microcontroller.

Assignees

• Egalax_Empia Tech Inc

Inventors

• Lin Po-Chuan

Classifications

• G06F3/044

  by capacitive means · CPC title

• G06F2203/04104

  Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger · CPC title

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/0488

  using a touch-screen or digitiser, e.g. input of commands through traced gestures · CPC title

• G06F3/04166

  Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184) · CPC title