Touch detection method and device

• US 9,785,300 B2
• Filed: 06/05/2013
• Issued: 10/10/2017
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: Spreadtrum Communications USA
• Original Assignee: Spreadtrum Communications USA
• Inventors: Yu, Huawei
• Primary Examiner(s): Bolotin, Dmitriy
• Application Number:
  US14/239,921
• Publication Number:
  US 20160162078A1
• Time in Patent Office: 1,588 Days
• Field of Search: 345173, 345174
• CPC Class Codes: G06F 2203/04104 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 Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

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.

Claims

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 Δ

x between the two touch points in a direction of the first axis based on following equation;

10. The method according to claim 1, 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 second resistive layer is greater than the difference between the voltages of the two electrodes on the first 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 second resistive layer.

11. The method according to claim 1, wherein the selected set of indeterminate coordinates defines two touch points as:

one touch point which is close to one electrode of one resistive layer which has a larger voltage and close to one electrode of the other resistive layer which is connected to a high level when the other resistive layer is biased; and

another touch point which is close to the other electrode of the one resistive layer which has a smaller voltage and close to the other electrode of the other resistive layer which is grounded when the other resistive layer is biased.

12. A touch detection device, comprising:

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 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, 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 the actual coordinate determining unit comprises a first actual coordinate determining unit, adapted for 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, 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.

13. The touch detection device according to claim 12, further comprising an indicator signal generating unit, adapted for comparing actual coordinates of two groups of the touch points and generating an indicator signal.

14. The touch detection device according to claim 13, wherein the indicator signal generating unit comprises:

a comparing sub-unit, adapted for comparing the actual coordinates of the two groups of the touch points to determine a change of touch, where the change of touch comprises a change in angle or a change in distance; and

a generating sub-unit, adapted for generating the indicator signal based on the change of touch.

15. The touch detection device according to claim 13, 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.

16. The touch detection device according to claim 12, 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, 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.

17. The touch detection device according to claim 16, wherein the associated point determining unit comprises a bias unit, adapted for 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.

18. The touch detection device according to claim 12, wherein the distance determining unit is adapted for:

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.

19. The touch detection device according to claim 18, 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 second resistive layer, or by measuring the voltage or current between the electrodes on the first or second resistive layer.

20. The touch detection device according to claim 18, wherein the distance determining unit comprises:

a first distance determining sub-unit, adapted for calculating a distance Δ

x between the two touch points in a direction of the first axis based on following equation;

21. The touch detection device according to claim 12, wherein the actual coordinate determining unit comprises a second actual coordinate determining unit, adapted for 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 second resistive layer, when the difference between the voltages of the two electrodes on the second resistive layer is greater than the difference between the voltages of the two electrodes on the first resistive layer.

22. The touch detection device according to claim 12, wherein the selected set of indeterminate coordinates defines two touch points as:

one touch point which is close to one electrode of one resistive layer which has a larger voltage and close to one electrode of the other resistive layer which is connected to a high level when the other resistive layer is biased; and

another touch point which is close to the other electrode of the one resistive layer which has a smaller voltage and close to the other electrode of the other resistive layer which is grounded when the other resistive layer is biased.