DISPLAY DEVICE HAVING OPTICAL SENSING FRAME AND METHOD FOR DETECTING TOUCH USING THE SAME

• US 20110254809A1
• Filed: 10/21/2010
• Published: 10/20/2011
• Est. Priority Date: 10/22/2009
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Jang, Hyung-Uk, Sohn, Min-Ho, Yu, Byung Chun
• Granted Patent: US 8,624,876 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A display device having an optical sensing frame, including a display panel; at least one waveguide unit arranged at two adjacent sides of the display panel, the waveguide unit having a stacked structure, the stacked structure including a light-emitting layer, and a light-receiving layer to receive reflected light, and a plurality of retroreflectors arranged at opposing sides of the waveguide unit.

Claims

1. A display device having an optical sensing frame, comprising:

a display panel;

at least one waveguide unit arranged at two adjacent sides of the display panel, the waveguide unit having a stacked structure, the stacked structure including a light-emitting layer, and a light-receiving layer to receive reflected light; and

a plurality of retroreflectors arranged at opposing sides of the waveguide unit.

2. The display device according to claim 1 wherein the light-emitting layer emits infrared light.

3. The display device according to claim 1 wherein the plurality of retroreflectors operate to return reflected light to the light receiving layer.

4. The display device according to claim 1 wherein the light-emitting layer includes a first plurality of optical fibers, and the light-receiving layer includes a second plurality of optical fibers, light emitted from an optical fiber of the light emitting layer being received by a corresponding optical fiber of the light receiving layer.

5. The display device according to claim 1 wherein the light-emitting layer includes a first plurality of optical fibers, each of the first plurality of optical fibers being connected to a first type of optical lens, and the light-receiving layer includes a second plurality of optical fibers, each of the second plurality of optical fibers being connected to a second type of optical lens.

6. The display device according to claim 5 wherein the first type of optical lens is a light focusing optical lens, and the second type of optical lens is a narrow viewing angle optical lens.

7. The display device according to claim 1 further comprising a case enclosing the display panel, the waveguide unit, and the plurality of retroreflectors.

8. The display device according to claim 7, wherein the case includes a case top portion on the display panel, each of the waveguide unit and retroreflector unit disposed between the case top potion and the display panel.

9. The display device according to claim 7, wherein a first supporter is disposed between the waveguide unit and the display panel and a second supporter is disposed between the retroreflector unit and the display panel.

10. The display device according to claim 1, wherein the light-emitting layer of the waveguide unit comprises:

an infrared LED to emit infrared light;

a light splitter to distribute light emitted from the infrared LED; and

a plurality of optical fibers allowing light split from the infrared LED to be transmitted along X and Y axes.

11. The display device according to claim 1, wherein the light-receiving layer of the waveguide unit comprises:

a plurality of optical fibers to receive light from the retroreflector; and

at least one optical detector connected to the plurality of optical fibers.

12. The display device according to claim 1, wherein the retroreflector comprises:

an optical filter layer to remove light received from a source other than the light-emitting layer; and

a retroreflector prism layer to reflect light received from the light-emitting layer.

13. A method for fabricating a display device having an optical sensing frame, comprising the steps of:

providing a display panel;

providing at least one waveguide unit arranged at two adjacent sides of the display panel, the waveguide unit having a stacked structure, the stacked structure including a light-emitting layer, and a light-receiving layer to receive reflected light; and

providing a plurality of retroreflectors arranged at opposing sides of the waveguide unit.

14. The method for fabricating a display device according to claim 13 wherein the light-emitting layer emits infrared light.

15. The method for fabricating a display device according to claim 13 wherein the plurality of retroreflectors operate to return reflected light to the light receiving layer.

16. The method for fabricating a display device according to claim 13 wherein the light-emitting layer includes a first plurality of optical fibers, and the light-receiving layer includes a second plurality of optical fibers, light emitted from an optical fiber of the light emitting layer being received by a corresponding optical fiber of the light receiving layer.

17. The method for fabricating a display device according to claim 13 wherein the light-emitting layer includes a first plurality of optical fibers, each of the first plurality of optical fibers being connected to a first type of optical lens, and the light-receiving layer includes a second plurality of optical fibers, each of the second plurality of optical fibers being connected to a second type of optical lens.

18. The method for fabricating a display device according to claim 17 wherein the first type of optical lens is a light focusing optical lens, and the second type of optical lens is a narrow viewing angle optical lens.

19. The method for fabricating a display device according to claim 13 further comprising the step of providing a case enclosing the display panel, the waveguide unit, and the plurality of retroreflectors.

20. The method for fabricating a display device according to claim 19, wherein the case includes a case top portion on the display panel, each of the waveguide unit and retroreflector unit disposed between the case top potion and the display panel.

21. The method for fabricating a display device according to claim 19, wherein a first supporter is disposed between the waveguide unit and the display panel and a second supporter is disposed between the retroreflector unit and the display panel.

22. The method for fabricating a display device according to claim 13, wherein the light-emitting layer of the waveguide unit is fabricated by:

providing an infrared LED to emit infrared light;

providing a light splitter to distribute light emitted from the infrared LED; and

providing a plurality of optical fibers allowing light split from the infrared LED to be transmitted along X and Y axes.

23. The method for fabricating a display device according to claim 13, wherein the light-receiving layer of the waveguide unit is fabricated by:

providing a plurality of optical fibers to receive light from the retroreflector; and

providing at least one optical detector connected to the plurality of optical fibers.

24. The method for fabricating a display device according to claim 13, wherein the retroreflector is fabricated by:

providing an optical filter layer to remove light received from a source other than the light-emitting layer; and

providing a retroreflector prism layer to reflect light received from the light-emitting layer.

25. A method for detecting touch of a display device with an optical sensing frame, the method comprising the steps of:

preparing a display device having a waveguide unit arranged at adjacent two sides of the display panel, a retroreflector arranged at the remaining two sides of the display panel and a case to encase the display panel, the waveguide unit and the retroreflector, wherein the waveguide unit has a stacked structure including a light-emitting layer to emit infrared light and a light-receiving layer to receive the reflected light and thus detect touch;

touching a portion of the display panel using an imput element; and

allowing the waveguide unit to sense variations in reception amount of reflected light caused by the intervention of the input element in the touched portion and allowing the input element to block emitted light to prevent retro-reflection and thus detect presence of touch and the position thereof.