Display device having optical sensing frame and method for detecting touch using the same

• US 8,624,876 B2
• Filed: 10/21/2010
• Issued: 01/07/2014
• Est. Priority Date: 10/22/2009
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Yu, Byung-Chun, Sohn, Min-Ho, Jang, Hyung-Uk
• Primary Examiner(s): Eisen, Alexander
• Assistant Examiner(s): Patel, Sanjiv D
• Application Number:
  US12/909,388
• Publication Number:
  US 20110254809A1
• Time in Patent Office: 1,174 Days
• Field of Search: 178 1808- 1811, 345/173, 345/175, 385129-132, 385 33- 35
• 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;

a retroreflector unit including a plurality of retroreflectors arranged at opposing sides of the waveguide unit; and

a case enclosing the display panel, the waveguide unit, and the plurality of retroreflectors,

wherein the case includes a case top portion on the display panel, each of the waveguide unit and the retroreflector unit disposed between the case top portion and the display panel and overlapping a portion of the display panel, wherein the case top portion shields the waveguide unit and the retroreflector unit; and

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,

and 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.

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 light emitted from the first plurality of optical fibers of the light emitting layer is respectively received by the corresponding second plurality of optical fibers of the light receiving layer.

5. The display device according to claim 1, 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.

6. 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

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

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

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

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

8. 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.

9. A method for fabricating a display device having an optical sensing frame, comprising:

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;

providing a retroreflector unit including a plurality of retroreflectors arranged at opposing sides of the waveguide unit; and

providing a case enclosing the display panel, the waveguide unit, and the plurality of retroreflectors,

wherein the case includes a case top portion on the display panel, each of the waveguide unit and the retroreflector unit disposed between the case top portion and the display panel and overlapping a portion of the display panel, wherein the case top portion shields the waveguide unit and the retroreflector unit, and

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,

and 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.

10. The method for fabricating a display device according to claim 9, wherein the light-emitting layer emits infrared light.

11. The method for fabricating a display device according to claim 9, wherein the plurality of retroreflectors operate to return reflected light to the light receiving layer.

12. The method for fabricating a display device according to claim 9, wherein light emitted from the first plurality of optical fibers of the light emitting layer is respectively received by the corresponding second plurality of optical fibers of the light receiving layer.

13. The method for fabricating a display device according to claim 9, 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.

14. The method for fabricating a display device according to claim 9, 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 the plurality of optical fibers allowing light split from the infrared LED to be transmitted along X and Y axes.

15. The method for fabricating a display device according to claim 9, wherein the light-receiving layer of the waveguide unit is fabricated by:

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

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

16. The method for fabricating a display device according to claim 9, 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.

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

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, wherein the case includes a case top portion on the display panel, each of the waveguide unit and the retroreflector disposed between the case top portion and the display panel and overlapping a portion of the display panel;

touching a portion of the display panel using an input 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,

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,

and 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.