Electromagnetic-type touch panel, method for driving and detecting electromagnetic-type touch panel, and coordinate input device

A method for driving and detecting an electromagnetic-type touch panel, wherein the method is for detecting a touch position of an electromagnetic stylus, wherein the electromagnetic-type touch panel comprises a first substrate, a plurality of first coils extending in a first direction and a plurality of second coils extending in a second direction, wherein the first coils and the second coils are arranged on the first substrate;

• wherein the plurality of first coils are bundled into a plurality of subgroups of first coils, wherein the plurality of subgroups of first coils are divided into a first group of first coils comprising odd numbered subgroups and a second group of first coils comprising even numbered subgroups;
• wherein the plurality of second coils are bundled into a plurality of subgroups of second coils, wherein the plurality of subgroups of second coils are divided into a first group of second coils comprising odd numbered subgroups and a second group of second coils comprising even numbered subgroups;
• wherein the method for driving and detecting the electromagnetic-type touch panel comprises:
• performing a preliminary detection;
• and
• performing an accurate detection;
• wherein performing the preliminary detection comprises performing a preliminary detection for a second direction coordinate, wherein performing the preliminary detection for the second direction coordinate comprises:
• applying a first drive signal simultaneously to the first group of first coils, and causing the first group of first coils to emit a first electromagnetic signal to the electromagnetic stylus;
• receiving, by the second group of first coils, a first reflected electromagnetic signal which are generated by the electromagnetic stylus based on the first electromagnetic signal, from the electromagnetic stylus;
• generating, by the second group of first coils, a first induction signal based on the first reflected electromagnetic signal;
• detecting the first induction signal from the second group of first coils;
• and
• determining a preliminary value of the second direction coordinate of the touch position of the electromagnetic stylus based on the first induction signal;
• wherein performing the preliminary detection further comprises performing a preliminary detection for the first direction coordinate, and wherein performing the preliminary detection for the first direction coordinate comprises a process A or a process B:
• wherein the process A comprises:
• applying a second drive signal simultaneously to at least one of the first group of first coils and the second group of first coils, and causing at least one of the first group of first coils and the second group of first coils to emit a second electromagnetic signal;
• detecting a second induction signal from the first group of second coils or from the second group of second coils;
• and
• determining a preliminary value of the first direction coordinate of the touch position of the electromagnetic stylus based on the second induction signals;
• wherein the process B comprises:
• applying a second drive signal simultaneously to the first group of second coils and causing the first group of second coils to emit a second electromagnetic signal;
• detecting a second induction signal from the second group of second coils;
• and
• determining a preliminary value of the first direction coordinate of the touch position of the electromagnetic stylus based on the second induction signal;
• wherein performing the accurate detection comprises performing an accurate detection for the first direction coordinate, and performing the accurate detection for the first direction coordinate comprises:
• wherein the method for driving and detecting the electromagnetic-type touch panel further comprises:
• selecting one subgroup of second coils corresponding to the preliminary value of the first direction coordinate of the touch position of the electromagnetic stylus, P second coils before the one subgroup of second coils, and Q second coils after the one subgroup of second coils, sequentially applying a drive signal to the selected second coils;
• emitting a fourth electromagnetic signal;
• receiving a fourth electromagnetic signal from the electromagnetic stylus;
• generating a fourth induction signal, by each second coil applied with the drive signal;
• and
• determining an accurate value of the first direction coordinate of the touch position of the electromagnetic stylus based on the fourth induction signal, wherein P and Q are positive integers.

The method for driving and detecting the electromagnetic-type touch panel according to 7, wherein performing the accurate detection comprises performing an accurate detection for the second direction coordinate, and performing the accurate detection for the second direction coordinate comprises:

• selecting one subgroup of first coils corresponding to the preliminary value of the second direction coordinate of the touch position of the electromagnetic stylus, M first coils before the one subgroup of first coils, and N first coils after the one subgroup of first coils, sequentially applying a third drive signal to the selected first coils;
• emitting a third electromagnetic signal;
• receiving a third reflected electromagnetic signal from the electromagnetic stylus;
• generating a third induction signal, by each first coil applied with the third drive signal;
• and
• determining an accurate value of the second direction coordinate of the touch position of the electromagnetic stylus based on the third induction signal, wherein M and N are positive integers.

An electromagnetic-type touch panel for detecting a touch position of an electromagnetic stylus, wherein the touch panel comprising:

• a first substrate;
• a plurality of first coils arranged on the first substrate and extending in a first direction;
• a plurality of second coils arranged on the first substrate and extending in a second direction;
• and
• a drive circuit and a detection circuit;
• wherein the plurality of first coils are bundled into a plurality of subgroups of first coils, wherein the plurality of subgroups of first coils are divided into a first group of first coils comprising odd numbered subgroups and a second group of first coils comprising even numbered subgroups;
• wherein the first group of first coils connects to the drive circuit, simultaneously receives a first drive signal from the drive circuit and emits a first electromagnetic signal to the electromagnetic stylus;
• wherein the electromagnetic stylus then generates a first reflected electromagnetic signal;
• wherein the second group of first coils connects to the detection circuit via a first element, receives the first reflected electromagnetic signal, and generates a first induction signal;
• wherein the detection circuit detects the first induction signal when the first element is a wire, determines a preliminary value of a second direction coordinate of the touch position of the electromagnetic stylus based on the first induction signal;
• wherein the plurality of second coils are bundled into a plurality of subgroups of second coils, wherein the plurality of subgroups of second coils are divided into a first group of second coils comprising odd numbered subgroups and a second group of second coils comprising even numbered subgroups;
• wherein the first group of second coils simultaneously receives a second drive signal from the drive circuit and emits a second electromagnetic signal to the electromagnetic stylus;
• wherein the electromagnetic stylus then generates a second reflected electromagnetic signal;
• wherein the second group of second coils connects to the detection circuit via a third element, receives the second reflected electromagnetic signal, and generates a second induction signal;
• wherein the detection circuit detects the second induction signal when the third element is a wire, determines a preliminary value of a first direction coordinate of the touch position of the electromagnetic stylus based on the second induction signal;
• wherein the drive circuit further selects one subgroup of second coils corresponding to the preliminary value of the first direction coordinate of the touch position of the electromagnetic stylus, P second coils before the one subgroup of second coils, and Q second coils after the one subgroup of second coils, and sequentially applies a fourth drive signal to the selected second coils,
• wherein the selected second coils each is applied with the fourth drive signal, emits a fourth electromagnetic signal to the electromagnetic stylus, receives a fourth reflected electromagnetic signal from the electromagnetic stylus, and generates a third induction signal;
• and
• wherein the detection circuit detects the fourth induction signal, determines an accurate value of the first direction coordinate of the touch position of the electromagnetic stylus based on the fourth induction signal.