Light sensing assembly and interactive display device having the same

• US 8,860,694 B2
• Filed: 09/22/2011
• Issued: 10/14/2014
• Est. Priority Date: 03/09/2011
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Hwang, Seong-Mo, Lee, Moon-Gyu, Jang, Hyeon-Yong, Pyun, Jae-Jin, Lee, Il-Ho, Baek, Moon-Jung
• Primary Examiner(s): Sitta, Grant
• Application Number:
  US13/239,888
• Publication Number:
  US 20120229422A1
• Time in Patent Office: 1,118 Days
• Field of Search: 345/175, 345/156, 345/173
• US Class Current: 345/175
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• 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

A light sensing assembly includes a first light guide plate (“LGP”), a light-emitting diode (“LED”) part, an infrared LED part, a second LGP and a first sensor array. The LED part is at a side portion of the first LGP and emits white lights of a displayed image. The infrared LED part emits infrared lights of a detected touch. The second LGP is below the first LGP. The second LGP guides a path of the infrared lights of the detected touch inputted in accordance with a touch operation. The first sensor array is at a side portion of the second LGP and senses the reflected infrared lights which are guided by the second LGP.

Claims

1. A light sensing assembly comprising:

a first light guide plate;

a light-emitting diode part at a side portion of the first light guide plate, wherein the light-emitting diode part emits white lights and the first light guide plate guides a path of the white lights to a display panel which displays an image by using the white lights;

an infrared light-emitting diode part which emits infrared lights of a detected touch;

a second light guide plate below the first light guide plate, wherein the second light guide plate guides a path of the infrared lights of the detected touch which are inputted in accordance with a touch operation;

a third light guide plate below the first light guide plate and parallel with the second light guide plate, wherein the third light guide plate guides the path of the infrared lights of the detected touch inputted in accordance with the touch operation; and

a first sensor array at a side portion of the second light guide plate, wherein the first sensor array senses the infrared lights which are guided by the second light guide plate;

a second sensor array at a side portion of the third light guide plate, wherein the second sensor array senses the infrared lights which are guided by the third light guide plate,

wherein the first light guide plate is between the display panel, and the second and third light guide plates.

2. The light sensing assembly of claim 1, wherein the second light guide plate has a wedge shape.

3. The light sensing assembly of claim 2,

wherein the white light-emitting diode part and the infrared light-emitting diode part are at a first side surface of the first light guide plate, and

wherein the first side surface of the first light guide plate is parallel with a longitudinal direction of the first sensor array.

4. The light sensing assembly of claim 3, wherein the white light-emitting diode part and the infrared light-emitting diode part are further at a second side surface of the first light guide plate which faces the first side surface.

5. The light sensing assembly of claim 1, further comprising:

a first lenticular lens between the first sensor array and the second light guide plate.

6. The light sensing assembly of claim 1, wherein the second and third light guide plates have a wedge shape, respectively, and are symmetrical with respect to a center of the first light guide plate.

7. The light sensing assembly of claim 1, further comprising:

a second lenticular lens between the second sensor array and the third light guide plate.

8. The light sensing assembly of claim 1, wherein

the white light-emitting diode part is at a first side surface of the first light guide plate, and

the infrared light-emitting diode part is at a third side surface adjacent to the first side surface of the first light guide plate.

9. The light sensing assembly of claim 8, wherein

the white light-emitting diode part is further at a second side surface which faces the first side surface, and

the infrared light-emitting diode part is further at a fourth side surface which faces the third side surface.

10. The light sensing assembly of claim 1, further comprising:

a turning film between the first light guide plate, and the second and third light guide plates,

wherein the turning film reflects the white lights which are emitted from the first light guide plate and transmits the infrared lights of the detected touch which exit through surfaces of the first light guide plate, toward the second and third light guide plates.

11. An interactive display device comprising:

a display panel which displays an image;

a first light guide plate below the display panel;

a white light-emitting diode part adjacent to a side portion of the first light guide plate, wherein the white light-emitting diode part emits white lights and the first light guide plate guides a path of the white lights to the display panel which displays the image by using the white lights;

an infrared light-emitting diode part which emits infrared lights;

a second light guide plate below the first light guide plate, wherein the second light guide plate guides a path of the infrared lights reflected in a touch operation at the display panel, to a first sensor array;

a third light guide plate below the first light guide plate and parallel with the second light guide plate, wherein the third light guide plate guides the path of the infrared lights reflected in the touch operation at the display panel to a second sensor array;

the first sensor array at a side portion of the second light guide plate, wherein the first sensor array senses the infrared lights which are guided by the second light guide plate, and

the second sensor array at a side portion of the third light guide plate, wherein the second sensor array senses the infrared lights which are guided by the third light guide plate,

wherein the first light guide plate is between the display panel, and the second and third light guide plates.

12. The interactive display device of claim 11, wherein the second light guide plate has a wedge shape.

13. The interactive display device of claim 11, wherein the first sensor array is substantially parallel with the infrared light-emitting diode part.

14. The interactive display device of claim 11, further comprising:

a turning film between the first light guide plate, and the second and third light guide plates,

wherein the turning film reflects the white lights emitted from the first light guide plate, toward the display panel, and transmits the reflected infrared lights which exit through surfaces of the first light guide plate, toward the second and third light guide plates.

15. The interactive display device of claim 11, further comprising:

a cover glass on the display panel which opposes the first light guide plate,

wherein the infrared light-emitting diode part is adjacent to a side portion of the cover glass.

16. The interactive display device of claim 15, wherein

the white light-emitting diode part is respectively at each of first sides of the first light guide plate, which face each other, and

the infrared light-emitting diode part is respectively at each of first sides of the cover glass, which face each other.

17. The interactive display device of claim 16, wherein

the first sides of the first light guide plate and the first sides of the cover glass are adjacent to each other in a plan view, such that the white light-emitting diode part at a side portion of the first light guide plate and the infrared light-emitting diode part at a side portion of the cover glass define a rectangular shape when viewed in the plan view.

18. An interactive display device comprising:

a display panel which displays an image;

a first light guide plate below the display panel;

a white light-emitting diode part at a side portion of the first light guide plate, wherein the white light-emitting diode part emits white lights and the first light guide plate guides a path of the white lights to the display panel which displays the image;

an infrared light-emitting diode part at a first side of the first light guide plate, wherein the infrared light-emitting diode part emits infrared lights;

a second light guide plate below a first area of the first light guide plate, wherein the second light guide plate guides a path of the infrared lights reflected in a touch operation at the display panel;

a third light guide plate below a second area of the first light guide plate different than the first area, wherein the third light guide plate guides a path of the reflected infrared lights;

a first sensor array at a first side portion of the second light guide plate, wherein the first sensor array senses the reflected infrared lights which are guided by the second light guide plate; and

a second sensor array at a first side portion of the third light guide plate, wherein the second sensor array senses the reflected infrared lights which are guided by the third light guide plate,

wherein the first light guide plate is between the display panel, and the second and third light guide plates.

19. The interactive display device of claim 18, wherein the second and third light guide plates have a wedge shape, respectively, and are symmetrical with respect to a center of the first light guide plate.

20. The interactive display device of claim 18, further comprising:

a first lenticular lens between the first sensor array and the second light guide plate; and

a second lenticular lens between the second sensor array and the third light guide plate.