METHOD OF DETECTING TOUCH POSITION, TOUCH POSITION DETECTING APPARATUS FOR PERFORMING THE METHOD AND DISPLAY APPARATUS HAVING THE TOUCH POSITION DETECTING APPARATUS

• US 20110163997A1
• Filed: 11/05/2010
• Published: 07/07/2011
• Est. Priority Date: 01/07/2010
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: KIM, Guk-Hyun
• Granted Patent: US 9,024,914 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• 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

Abstract

In a method of detecting a touch position, light is emitted. A plurality of light beams derived from the emitted light is received. The light beams have different paths from each other. The light beams are partially reflected according to a touch. The touch position is detected based on an amount of light in the received light beams. According to the present invention, the touch positions of several touching elements may be individually detected.

Claims

1. A method of detecting a touch position, the method comprising:

emitting light;

receiving a plurality of light beams derived from the light, the light beams having different paths from each other, the light beams being partially reflected according to a touch; and

detecting the touch position based on an amount of light in the received light beams.

2. The method of claim 1, wherein the light beams are individually received.

3. The method of claim 1, wherein the light beams are partially reflected by a plurality of touching elements, and the touching elements have refractive indices different from each other.

4. The method of claim 1, wherein the light is emitted by a plurality of light emitting elements that each emit one or more light beams.

5. The method of claim 1, wherein the light beams are derived from the light by passing the emitted light through an incident surface of a light waveguide, the incident surface having a plurality of inclined surfaces.

6. The method of claim 1, wherein detecting the touch position comprises:

detecting the touch position of an n-th touching element based on an amount of light in an n-th light beam;

detecting the touch positions of the n-th touching element and an (n−

1)-th touching element based on an amount of light in an (n−

1)-th light beam; and

detecting the touch position of the (n−

1)-th touching element using the touch position of the detected n-th touching element and the touch positions of the detected n-th and (n−

1)-th touching elements,

where n is a natural number.

7. A touch position detecting apparatus comprising:

a light emitting part emitting light;

a light waveguide comprising;

a light incident surface disposed adjacent to the light emitting part, the light being incident to the light incident surface;

a touch surface touched by a touch; and

a light exiting surface opposite to the light incident surface, a plurality of light beams derived from the light exiting the light exiting surface, the light beams having different paths from each other, the light beams being partially reflected according to the touch;

a light receiving part adjacent to the light exiting surface and comprising a plurality of light receiving elements respectively receiving the light beams exiting from the light exiting surface; and

a detecting part detecting a touch position based on an amount of the light in the light beams received by the light receiving part.

8. The touch position detecting apparatus of claim 7, wherein the light emitting part comprises a plurality of light emitting elements emitting the light beams.

9. The touch position detecting apparatus of claim 8, wherein light emitting surfaces of the light emitting elements emit light in different directions from each other.

10. The touch position detecting apparatus of claim 9, wherein the light incident surface is substantially perpendicular to the touch surface of the light waveguide.

11. The touch position detecting apparatus of claim 10, wherein the light exiting surface is substantially perpendicular to the touch surface of the light waveguide.

12. The touch position detecting apparatus of claim 9, wherein the light incident surface is connected to the touch surface of the light waveguide with a first inclination angle.

13. The touch position detecting apparatus of claim 12, wherein the light exiting surface is connected to the touch surface of the light waveguide with a second inclination angle, and the first inclination angle is substantially equal to the second inclination angle.

14. The touch position detecting apparatus of claim 7, wherein the light incident surface of the light waveguide comprises a plurality of first inclined surfaces, and the first inclined surfaces convert the light emitted from the light emitting part into the light beams.

15. The touch position detecting apparatus of claim 14, wherein the light exiting surface of the light waveguide comprises a plurality of second inclined surfaces, and the second inclined surfaces respectively face the first inclined surfaces.

16. A display apparatus comprising:

a light emitting part emitting light;

a light waveguide comprising;

a light incident surface disposed adjacent to the light emitting part, the light being incident to the light incident surface;

a touch surface touched by a touch; and

a light exiting surface opposite to the light incident surface, a plurality of light beams exiting the light exiting surface, the light beams having different paths from each other, the light beams being partially reflected according to the touch;

a light receiving part adjacent to the light exiting surface and comprising a plurality of light receiving elements respectively receiving the light beams exiting from the light exiting surface; and

a detecting part detecting a touch position based on an amount of light in the light beams received by the light receiving part; and

a display panel disposed under the light waveguide and displaying an image according to the touch position.

17. The display apparatus of claim 16, wherein the light emitting part comprises a plurality of light emitting elements emitting the light beams.

18. The display apparatus of claim 17, wherein the light incident surface is connected to the touch surface of the light waveguide with a first inclination angle, the light exiting surface is connected to the touch surface of the light waveguide with a second inclination angle, and the first inclination angle is substantially equal to the second inclination angle.

19. The display apparatus of claim 16, wherein the light incident surface of the light waveguide comprises a plurality of first inclined surfaces, and the first inclined surfaces convert the light emitted from the light emitting part into the light beams.

20. The display apparatus of claim 19, wherein the light exiting surface of the light waveguide comprises a plurality of second inclined surfaces, and the second inclined surfaces respectively face the first inclined surfaces.