TOUCH SCREEN PANEL AND DETECTING METHOD OF TOUCH POSITION USING THE SAME

• US 20150109259A1
• Filed: 04/11/2014
• Published: 04/23/2015
• Est. Priority Date: 10/23/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: HONG, Won-Ki, PARK, Seung-Won, LEE, Jong Seo
• Granted Patent: US 9,141,232 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• 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 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A touch screen panel includes: a wave guide; a first transmitter at a first end of the wave guide to output an ultrasonic or light wave into the wave guide; a second transmitter at a second end of the wave guide to output the ultrasonic or light wave into the wave guide; a first receiver at the first end to receive the ultrasonic or light wave from the second transmitter and generate a first receipt signal; a second receiver at the second end to receive the ultrasonic or light wave and generate a second receipt signal; and a controller connected to the first receiver and the second receiver to detect a touch position on the wave guide using a time difference between a time point at which the first receipt signal is varied and a time point at which the second receipt signal is varied.

Claims

1. A touch screen panel comprising:

a wave guide;

a first transmitter disposed at a first end of the wave guide and which outputs one of an ultrasonic wave and a light wave into the wave guide;

a second transmitter disposed at a second end of the wave guide and which outputs the one of the ultrasonic wave and the light wave into the wave guide;

a first receiver disposed at the first end of the wave guide and which receives the one of the ultrasonic wave and the light wave from the second transmitter and generates a first receipt signal;

a second receiver disposed at the second end of the wave guide and which receives the one of the ultrasonic wave and the light wave from the first transmitter and generates a second receipt signal; and

a controller connected to the first receiver and the second receiver and which detects a touch position on the wave guide using a time difference between a first time point at which the first receipt signal is varied and a second time point at which the second receipt signal is varied.

2. The touch screen panel of claim 1, wherein the wave guide comprises a material having a refractive index which is different from a refractive index of air.

3. The touch screen panel of claim 2, wherein the wave guide comprises a transparent glass material or a transparent plastic material.

4. The touch screen panel of claim 2, wherein the wave guide has a tube shape having a zigzag shape which overlaps a surface of the touch screen panel.

5. The touch screen panel of claim 4, wherein the wave guide has a width of about 2 millimeters or less.

6. The touch screen panel of claim 5, wherein a space between two adjacent extending portions of the zigzag shape of the wave guide is filled with air.

7. The touch screen panel of claim 5, wherein a space between adjacent extending portions of the zigzag shape of the wave guide is filled with an index matching material having a refractive index which is less than the refractive index of the material of the wave guide.

8. The touch screen panel of claim 7, wherein the first receiver and the second receiver receive the one of the ultrasonic wave and the light wave totally reflected and transferred through the wave guide.

9. The touch screen panel of claim 1, wherein the controller detects the touch position as a position away from a middle position of the wave guide by a distance which is obtained by multiplying the time difference between the first time point and the second time point by a speed of the ultrasonic wave or the light wave.

10. The touch screen panel of claim 1, wherein the first transmitter and the second transmitter output the one of the ultrasonic wave and the light wave as a continuous wave.

11. The touch screen panel of claim 1, wherein the first transmitter and the second transmitter output the one of the ultrasonic wave and the light wave as a pulse wave.

12. The touch screen panel of claim 11, wherein the first transmitter and the second transmitter output the one of the ultrasonic wave and the light wave with different frequencies.

13. The touch screen panel of claim 12, wherein the first transmitter and the second transmitter output the one of the ultrasonic wave and the light wave with a frequency hopping method.

14. The touch screen panel of claim 11, wherein the first receiver and the second receiver use frequency modulation which modifies the one of the ultrasonic wave and the light wave to have a predetermined amplitude.

15. The touch screen panel of claim 1, wherein

the controller detects one touch position using a time difference between an earliest time point among time points at which the first receipt signal is varied and a latest time point among time points at which the second receipt signal is varied, and

the controller detects another touch position using a time difference between a second earliest time point among the time points at which the first receipt signal is varied and a second latest time point among the time points at which the second receipt signal is varied.

16. The touch screen panel of claim 1, wherein the controller detects a touch pressure on the wave guide by detecting magnitudes of the first receipt signal and the second receipt signal which are varied.

17. A method of detecting a touch position on a touch screen panel, the method comprising:

receiving a first ultrasonic wave transferred from a first end of a wave guide of the touch screen panel to a second end of the wave guide;

receiving a second ultrasonic wave transferred from the second end of the wave guide to the first end of the wave guide;

generating a first receipt signal based on the first ultrasonic wave;

generating a second receipt signal based on the second ultrasonic wave; and

detecting a touch position on the wave guide using a time difference between a first time point at which the first receipt signal is varied and a second time point at which the second receipt signal is varied.

18. The method of claim 17, wherein the detecting the touch position on the wave guide comprises detecting the touch position as a position away from a middle position of the wave guide by a distance which is obtained by multiplying the time difference between the first time point and the second time point by a speed of the first and second ultrasonic waves.

19. The method of claim 17, wherein the detecting the touch position on the wave guide comprises:

detecting one touch position using a time difference between an earliest time point among time points at which the first receipt signal is varied and a latest time point among time points at which the second receipt signal is varied; and

detecting another touch position using a time difference between a second earliest time point among the time points at which the first receipt signal is varied and a second latest time point among the time points at which the second receipt signal is varied.

20. The method of claim 17, further comprising:

detecting a touch pressure on the wave guide by detecting magnitudes of the first receipt signal and the second receipt signal which are varied.