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

Patent metadata

Field	Value
Publication number	US-9836135-B2
Application number	US-201414516519-A
Country	US
Kind code	B2
Filing date	Oct 16, 2014
Priority date	Mar 28, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

An touch panel detecting a touch position of an electromagnetic stylus is disclosed. The touch panel includes first and second coils, and drive and detection circuits. The first coils include a plurality of subgroups of first coils, which includes a first group of first coils and a second group of first coils. The first group of first coils includes at least one subgroup of first coils, and the second group of first coils includes at least one subgroup of first coils. In addition, subgroups of the first and second groups of first coils are alternately arranged. The first group of first coils receive a signal from the drive circuit and emit signals, the second group of first coils receive signals from the stylus and generate induction signals, and the detection circuit determines a value of a coordinate of the touch position of the stylus based on the induction signals.

First claim

What is claimed is:

1. An electromagnetic-type touch panel for detecting a touch position of an electromagnetic stylus, 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 at least one of the first group of first coils and the second group of first coils connects to the drive circuit, simultaneously receive 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 at least one of the first group of second coils and the second group of second coils connects to the detection circuit via a second element, receives the second reflected electromagnetic signal, and generates a second induction signal;
wherein the detection circuit detects the second induction signal when the second 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 fourth 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, wherein P and Q are positive integers.

2. The electromagnetic-type touch panel according to claim 1 ,
wherein the first element connecting the second group of first coils to the detection circuit is a first selection switch unit, the first selection switch unit is off when the first group of first coils emits the first electromagnetic signal, and the first selection switch unit is on when the first group of first coils does not emit the first electromagnetic signal, or
the detection circuit further comprises a first signal filtering unit configured to remove a signal received from the second group of first coils when the first group of first coils emits the first electromagnetic signal.

3. The electromagnetic-type touch panel according to claim 1 ,
wherein the first group of first coils receive the first drive signal from the drive circuit and emits the first electromagnetic signal to the electromagnetic stylus;
wherein a process
wherein the electromagnetic stylus then generates the first reflected electromagnetic signal, wherein the second group of first coils connects to the detection circuit via the first element, receives the first reflected electromagnetic signal, and generates the first induction signal;

and a process
wherein the electromagnetic stylus generates the second reflected electromagnetic signal; wherein the second group of second coils connects to the detection circuit via the second element, receives the second reflected electromagnetic signal, and generates the second induction signal;

are performed simultaneously.

4. The electromagnetic-type touch panel according to claim 1 ,
the second element connecting the at least one of the first group of second coils and the second group of second coils to the detection circuit is a second selection switch unit, wherein the second selection switch unit is off when at least one of the first group of first coils and the second group of first coils emits the second electromagnetic signal, and wherein the second selection switch unit is on when at least one of the first group of first coils and the second group of first coils does not emit the second electromagnetic signal; or
wherein the detection circuit further comprises a second signal filtering unit configured to remove a signal received from at least one of the first group of second coils and the second group of second coils when at least one of the first group of first coils and the second group of first coils emits the second electromagnetic signal.

5. The electromagnetic-type touch panel according claim 1 ,
wherein the drive circuit further selects 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, and sequentially applies a third drive signal to the selected first coils,
wherein the selected first coils each is applied with the third drive signal, emits a third electromagnetic signal to the electromagnetic stylus, receives a third reflected electromagnetic signal from the electromagnetic stylus, and generates a third induction signal, and
wherein the detection circuit detects the third induction signal, determines 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.

6. A coordinate input device, comprising an electromagnetic stylus and an electromagnetic-type touch panel for detecting a touch position of the electromagnetic stylus according to claim 1 .

7. 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

Assignees

• Shanghai Tianma Microelectronics Co Ltd
• Tianma Microelectronics Co Ltd

Inventors

• Lu Feng
• Yao Qijun
• Zhang Xianxiang

Classifications

• G01D9/20

  the recording element, e.g. stylus, being controlled in accordance with time and the recording medium, e.g. paper roll, being controlled in accordance with the variable · CPC title

• G06F3/03545 Primary

  Pens or stylus · CPC title

• G06F3/0418

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G01D5/2073

  by movement of a single coil with respect to two or more coils · CPC title

• G06F3/046

  by electromagnetic means · CPC title