Touch sensing method, recording medium in which program for realizing the same is recorded, and touch sensing system

Patent metadata

Field	Value
Publication number	US-9377883-B2
Application number	US-201113240955-A
Country	US
Kind code	B2
Filing date	Sep 22, 2011
Priority date	Jan 18, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A touch sensing method for a touch screen including an image display device with a touch-sensitive screen. The method includes a filtering process that includes calculating an output signal of an n th frame from a sensing signal of the n th frame output from a touch sensing unit configured to sense touches of the touch-sensitive screen, the calculating using an equation

F ( n )= I ( n )× W ( n )+ F ( n −1)×[1− W ( n )],

wherein F(n) represents the output signal of the n th frame, I(n) represents the sensing signal of the n th frame, F(n−1) represents an output signal of an (n−1) th frame, and W(n) represents a filtering coefficient; and outputting the output signal of the n th frame to an output end. The filtering coefficient is calculated by an equation

W ⁡ ( n ) =  I ⁡ ( n ) - F ⁡ ( n - 1 )  R ,
wherein R is a scale constant. The touch sensing method has high touch sensitivity in an environment with heavy noise while being capable of correctly detecting touch coordinates.

First claim

What is claimed is:

1. A touch sensing method for a touch-sensitive screen of an image display device, the touch sensing method comprising, for each frame after a first frame of a plurality of frames:
calculating an output touch signal of an n th frame, n≧2, from a touch sensing signal of the n th frame output from a touch sensing unit configured to sense touches of the touch-sensitive screen to perform a filtering process, the calculating using an equation

F
⁡

(
n
)

=

I
⁡

(
n
)

×



I
⁡

(
n
)

-

F
⁡

(

n
-
1

)



R

+

F
⁡

(

n
-
1

)

×

(

1
-



I
⁡

(
n
)

-

F
⁡

(

n
-
1

)



R

)

,

wherein F(n) represents the output touch signal of the n th frame, I(n) represents the touch sensing signal of the n th frame, F(n−1) represents an output touch signal of an (n−1) th frame, and R represents a scale constant satisfying

0
<



I
⁡

(
n
)

-

F
⁡

(

n
-
1

)



R

<
1

;

and
outputting the output touch signal of the n th frame to an output end.

2. The touch sensing method as claimed in claim 1 , further comprising:
in a first condition process, receiving the touch sensing signal of the n th frame output from the touch sensing unit, performing the filtering process when the touch sensing signal of the n th frame is no more than a first reference value, and transmitting the touch sensing signal to a second condition process when the touch sensing signal of the n th frame is larger than the first reference value;
in the second condition process, transmitting the touch sensing signal to a third condition process when a sum obtained by adding the touch sensing signal transmitted from the first condition process to touch sensing signals of adjacent coordinates is no more than a second reference value, and outputting the touch sensing signal to the output end as the output touch signal of the n th frame when the sum is larger than the second reference value; and
in the third condition process, performing the filtering process when the touch sensing signal transmitted from the second condition process is no more than a third reference value, and outputting the touch sensing signal to the output end as the output touch signal of the n th frame when the touch sensing signal transmitted from the second condition process is larger than the third reference value.

3. The touch sensing method as claimed in claim 2 , wherein the third reference value is larger than the first reference value.

4. The touch sensing method as claimed in claim 2 , wherein the second reference value is larger than the first reference value and the third reference value.

5. The touch sensing method as claimed in claim 1 , further comprising:
replacing the output touch signal of the n th frame output to the output end by a sum obtained by adding touch sensing signals of adjacent coordinates to each other;
replacing the sum by 0 when the sum is no more than a fourth reference value and replacing the sum by 1 when the sum is larger than the fourth reference value to perform a comparing process; and
multiplying the 0 or 1 generated by the comparing process by the output touch signal of the n th frame.

6. A non-transitory computer readable medium for recording a program of realizing a touch sensing method for a touch-sensitive screen of an image display device, the touch sensing method comprising, for each frame after a first frame of a plurality of frames:
calculating an output touch signal of an n th frame, n≧2, from a touch sensing signal of the n th frame output from a touch sensing unit configured to sense touches of the touch-sensitive screen to perform a filtering process, the calculating u

Assignees

• Lee Dong-Won
• Hwang Hee-Chul
• Park Jong-Woong
• Samsung Display Co Ltd

Inventors

• Lee Dong-Won
• Hwang Hee-Chul
• Park Jong-Woong

Classifications

• G06F3/0418 Primary

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

• G06F3/044

  by capacitive means · CPC title

• G06F3/041 Primary

  Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means · CPC title

• G06F17/10

  Complex mathematical operations {(function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544)} · CPC title

• G06F3/04182 Primary

  Filtering of noise external to the device and not generated by digitiser components · CPC title