Touch detection method and device

Patent metadata

Field	Value
Publication number	US-9785300-B2
Application number	US-201314239921-A
Country	US
Kind code	B2
Filing date	Jun 5, 2013
Priority date	Jun 5, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A touch detection method and device are provided. The method includes: obtaining coordinates of a point associated with touch points; obtaining distances between the touch points in a direction of an axis to be measured; determining indeterminate coordinates of the touch points based on the coordinates of the point associated with the touch points and the distances between the touch points in the direction of the axis to be measured; and determining actual coordinates of the touch points according to the indeterminate coordinates of the touch points. The device includes: an associated point determining unit, adapted for obtaining coordinates of a point associated with touch points; a distance determining unit, adapted for obtaining distances between the touch points in a direction of an axis to be measured; an indeterminate coordinate determining unit, adapted for determining indeterminate coordinates of the touch points based on the coordinates of the point associated with the touch points and the distances between the touch points in the direction of the axis to be measured; and an actual coordinate determining unit, adapted for determining actual coordinates of the touch points according to the indeterminate coordinates of the touch points.

First claim

What is claimed is:

1. A touch detection method, comprising: obtaining coordinates of a point associated with touch points; obtaining distances between the touch points in a direction of an axis to be measured; determining indeterminate coordinates of the touch points based on the coordinates of the point associated with the touch points and the distances between the touch points in the direction of the axis to be measured; and determining actual coordinates of the touch points according to the indeterminate coordinates of the touch points, wherein the number of the touch points is two, indeterminate coordinates of the touch points comprise two sets of indeterminate coordinates, each set comprises indeterminate coordinates of the two touch points, and determining actual coordinates of the touch points according to the indeterminate coordinates of the touch points comprises: selecting one set of indeterminate coordinates as the actual coordinates of the two touch points based on voltages of two electrodes on a first resistive layer of a touch screen or voltages of two electrodes on a second resistive layer of the touch screen, where the voltages of the two electrodes on the first resistive layer are the voltages of the two electrodes on the first resistive layer when the second resistive layer is biased, and the voltages of the two electrodes on the second resistive layer are the voltages of the two electrodes on the second resistive layer when the first resistive layer is biased;
wherein selecting one set of indeterminate coordinates as the actual coordinates of the two touch points based on the voltages of two electrodes on the first resistive layer or the voltages of two electrodes on the second resistive layer comprises:
when the difference between the voltages of the two electrodes on the first resistive layer is greater than the difference between the voltages of the two electrodes on the second resistive layer, selecting one set of indeterminate coordinates as the actual coordinates of the two touch points according to the voltages of the two electrodes on the first resistive layer.

2. The method according to claim 1 , further comprising: comparing actual coordinates of two groups of the touch points and generating an indicator signal.

3. The method according to claim 2 , wherein comparing the actual coordinates of two groups of the touch points and generating an indicator signal comprises: comparing the actual coordinates of the two groups of the touch points to determine a change of touch and generating the indicator signal, where the change of touch comprises a change in angle or a change in distance.

4. The method according to claim 2 , wherein the indicator signal indicates performing at least one operation in a shortcut menu which comprises zooming in, zooming out, rotation, page-turning, forward, backward, speeding up, slowing down and popping a current state.

5. The method according to claim 1 , wherein the coordinates of the point associated with the touch points comprise a coordinate on a first axis and a coordinate on a second axis,
where the coordinate on the first axis is obtained based on at least one of a first coordinate and a second coordinate, the first coordinate is relevant to the voltage of an electrode on the second resistive layer of the touch screen when the first resistive layer of the touch screen is biased, and the second coordinate is relevant to the voltage of another electrode on the second resistive layer when the first resistive layer is biased,
and where the coordinate on the second axis is obtained based on at least one of a third coordinate and a fourth coordinate, the third coordinate is relevant to the voltage of an electrode on the first resistive layer when the second resistive layer is biased, and the fourth coordinate is relevant to the voltage of another electrode on the first resistive layer when the second resistive layer is biased.

6. The method according to claim 5 , wherein biasing a resistive layer comprises:
applying a first voltage on an electrode on the first or second resistive layer; and applying a second voltage on another electrode on the first or second resistive layer, where the first voltage is larger than the second voltage.

7. The method according to claim 1 , wherein the obtaining distances between the touch points in a direction of an axis to be measured comprises:
measuring a voltage or current of an external resistor on each of the two resistive layers, respectively, or measuring a voltage or current between electrodes on each of the two resistive layers, respectively, so as to obtain resistance variations of the touch screen in directions of a first axis and a second axis; and
determining distances between the two touch points in the directions of the first axis and the second axis based on the resistance variations of the touch screen in the directions of the first axis and the second axis, respectively.

8. The method according to claim 7 , wherein the resistance variation of the touch screen in the direction of the first axis or the second axis is the difference between the resistances of the touch screen in the direction of the first axis or the second axis when the touch screen is touched or not touched, and the resistance of the touch screen in the direction of the first axis or the second axis when the touch screen is touched is obtained by measuring the voltage or current of the external resistor on the first or resistive layer, or by measuring the voltage or current between the electrodes on the first or second resistive layer.

9. The method according to claim 7 , wherein determining the distances between the two touch points in the directions of the first axis and the second axis based on the resistance variations of the touch screen in the directions of the first axis and the second axis, respectively, comprises:
calculating a distance Δx between the two touch points in a direction of the first axis based on following equation:

Δ
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⁢
x

=

Δ
⁢

⁢
R
⁢

⁢

x
⁡

(

K
⁢

⁢
x

+

K
⁢

⁢
y

)

+

(

Δ

Assignees

• Spreadtrum Comm Shanghai Co

Inventors

• Yu Huawei

Classifications

• 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

• G06F3/045 Primary

  using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact · CPC title

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title