Coordinate detection device and coordinate detection method

Patent metadata

Field	Value
Publication number	US-10635241-B2
Application number	US-201615737736-A
Country	US
Kind code	B2
Filing date	Jun 10, 2016
Priority date	Jun 19, 2015
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

[Problem] To detect touch coordinates, without detection errors and without using a special pen, on a substrate such as a touch panel. [Solution] This coordinate detection method comprises: calculating a ratio between the short-term average (STA) and long-term average (LTA) of output signals from at least three vibration detectors installed apart from each other at predetermined distances on a substrate which has a uniform thickness and is made from a homogeneous material that allows the propagation speeds of oscillating waves to be constant; calculating, as arrival times, the times at which the STA/LTA ratio of the three vibration detectors by oscillating waves generated by touching the substrate exceeds a predetermined threshold value; and calculating touch position coordinates on the basis of each of the arrival times, the propagation speed of the oscillating waves, and the distances at which the three vibration detectors are spaced apart from each other.

First claim

The invention claimed is:

1. A coordinates detection method including the following steps:
respectively determining a STA/LTA ratio to each of output signals from at least three oscillation detectors located apart from each other by a predetermined distance on a substrate, the STA/LTA ratio representing a ratio of a short term average to a long term average, wherein the short term average has a first predetermined cumulative time and the long term average has a second predetermined cumulative time that is longer than the first predetermined cumulative time as being set;
respectively determining from an oscillatory wave generated by touching said substrate, a time when each of said STA/LTA ratios of said at least three oscillation detectors has exceeded a predetermined threshold; and
determining touched position coordinates from said respective times, a propagation velocity of said oscillatory wave, and information on locations of said at least three oscillation detectors, wherein the first predetermined cumulative time for the short term average and the second predetermined cumulative time for the long term average are set such that the STA/LTA ratio at a time of touching the substrate exceeds the predetermined threshold, and wherein the first predetermined cumulative time and the second predetermined cumulative time are set based upon at least a material thickness of the substrate and a layout of the at least three oscillation detectors, the layout comprising positions of the at least three oscillation detectors relative to one another.

2. The coordinates detection method according to claim 1 , further including a step of:
determining said propagation velocity of said oscillatory wave before the determination of the STA/LTA ratio with said at least three oscillation detectors.

3. The coordinates detection method according to claim 2 , wherein an optimal cumulative time for said short term average and said long term average is configured to be automatically set through calibration.

4. The coordinates detection method according to claim 3 , wherein a plurality of different cumulative times is prepared for said short term average and said long term average before the determination of the STA/LTA ratio, so that the touched position coordinates, which correspond to various cumulative times, may be computed, depending on an output result by said touching.

5. The coordinates detection method of claim 1 , wherein the at least three oscillation detectors comprise four oscillation detectors; and
respectively determining, from each of said times, a required time taken for said oscillatory wave to reach from a touched position to each of said four oscillation detectors; and
determining the touched position coordinates from said respective required times, the propagation velocity of said oscillatory wave, and the information on the locations of three out of said four oscillation detectors.

6. A coordinates detection method including the following steps:
respectively determining a STA/LTA ratio to each of output signals from four oscillation detectors located apart from each other by a predetermined distance on a substrate, the STA/LTA ratio representing a ratio of a short term average to a long term average, wherein the short term average has a first predetermined cumulative time and the long term average has a second predetermined cumulative time that is longer than the first predetermined cumulative time as being set;
respectively determining from an oscillatory wave generated by touching said substrate, a time when each of said STA/LTA ratios of said four oscillation detectors has exceeded a predetermined threshold;
respectively determining, from each of said times, a required time taken for said oscillatory wave to reach from a touched position to each of said four oscillation detectors; and
determining touched position coordinates from said respective required times and information on locations of said four oscillation detectors, wherein determining the touched position coordinates further includes:
discriminating, based on said times, one among said four oscillation detectors at which said oscillatory wave has arrived earliest;
discriminating a quadrant of a rectangle that contains as an apex the location of said one oscillation detector at which said oscillatory wave has arrived earliest; and
selecting three out of said four oscillation detectors according to a sequence of said times when the oscillatory wave has arrived, and determining the touched position coordinates from the locations where said three oscillation detectors are located and the times when said three oscillation detectors detect the oscillatory wave.

7. A coordinates detection method including the following steps:
respectively determining a STA/LTA ratio to an output signal from each of oscillation detectors in a first incident direction detecting module and a second incident direction detecting module located apart from each other by a predetermined distance on a substrate, the STA/LTA ratio representing a ratio of a short term average to a long term average, wherein each of the short term average and the long term average has its own predetermined cumulative time as being set, each of said first and second incident direction detecting modules being comprised of three oscillation detectors;
respectively determining from an oscillatory wave generated by touching said substrate a time when each of said STA/LTA ratios for said three respective oscillation detectors in said first and second respective incident direction detecting modules has exceeded a predetermined threshold;
respectively computing, from each of said times, first and second angles for an incidence of said oscillatory wave upon said first and second incident direction detecting modules; and
computing touched position coordinates from said first and second angles and the coordinates of said first and second incident direction detecting modules.

8. The coordinates detection method according to claim 7 , including the following steps:
a step of computing arrival times at said three oscillation detectors located at apexes of a first isosceles right triangle constructing said first incident direction detecting module;
a step of respectively computing a difference between said arrival time at the oscillation detector located at the apex forming a right angle of said first isosceles right triangle and said arrival time at one of the other oscillation detectors located at one of two other apexes of said first isosceles right triangle, and a difference between said arrival time at the oscillation detector located at the apex forming the right angle and said arrival time at another of the other oscillation detectors located at the other of the two other apexes of said first isosceles right triangle, and computing from a ratio of the two differences of said arrival times said first angle for the incidence of said oscillatory wave upon said first incident direction detecting module;
a step of computing arrival times at said three oscillation detectors located at apexes of a second isosceles right triangle constructing said second incident direction detecting module;
a step of respectively computing a difference between said arrival time at the oscillation detector located at an apex forming a right angle of said second isosceles right triangle and said arrival time at one of the other oscillation detectors located at one of two other apexes of said second isosceles right triangle, and a difference between said arrival time at the oscillation detector located at the apex forming the right angle and said arrival time at another of the other oscillation detectors located at the other of the two other apexes of said second isosceles rig

Assignees

• Alab Inc
• Konami Digital Entertainment Co Ltd

Inventors

• Araki Masayuki
• Sugawara Tatsuya
• Takahama Hajime

Classifications

• G06F3/043 Primary

  using propagating acoustic waves · CPC title

• G06F3/0354

  with detection of two-dimensional [2D] relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D mice, trackballs, pens or pucks · CPC title

• G06F3/0433 Primary

  in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member · CPC title