INFRARED SENSOR INTEGRATED IN A TOUCH PANEL

• US 20110169779A1
• Filed: 03/11/2011
• Published: 07/14/2011
• Est. Priority Date: 11/27/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bathiche, Steven N., Izadi, Shahram, Hodges, Stephen Edward, Boer, Willem den
• Granted Patent: US 8,411,070 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing

Abstract

An infrared source is configured to illuminate the underside of one or more objects on or above a touchable surface of a touch panel. Infrared light reflected from the underside of the object(s) is detected by an infrared sensor integrated in the touch panel below the touchable surface.

Claims

1. A touch panel system comprising:

a display configured to display an image viewable via a touchable surface of the touch panel system;

at least one infrared source integrated in the touch panel system and configured to direct infrared radiation towards and through the touchable surface for illuminating one or more objects that are in contact with or adjacent to the touchable surface with infrared radiation; and

a touch panel having integrated therein infrared sensors that are distributed throughout the touch panel parallel to the touchable surface, wherein;

the infrared sensors are sensitive to infrared radiation incident on the infrared sensors which is directed by the at least one infrared source towards and through the touchable surface and reflected from above the touchable surface by the one or more objects,

output from a plurality of the infrared sensors is processed to detect an infrared image, and

detection of the infrared image based on the output of the plurality of infrared sensors does not conflict with the image visibly displayed on the display of the touch panel system.

2. The touch panel system of claim 1, further comprising:

a backlight arranged below the touch panel, wherein the backlight comprises the at least one infrared source and at least one visible light source.

3. The touch panel system of claim 1, further comprising:

a frontlight arranged above the touch panel, wherein the frontlight comprises the at least one infrared source, and the touchable surface comprises a surface of the frontlight.

4. The touch panel system of claim 1, wherein the display is a liquid crystal display.

5. The touch panel system of claim 4, wherein the liquid crystal display comprises one of an active matrix backplane, an active matrix frontplane, a passive matrix backplane, and a passive matrix frontplane.

6. The touch panel system of claim 1, wherein the display is an organic light emitting diode display.

7. The touch panel system of claim 6, wherein the infrared source is an organic light emitting diode.

8. The touch panel system of claim 6, wherein the infrared sensors comprise infrared-sensitive organic photosensors.

9. The touch panel system of claim 1, wherein the infrared sensors comprise thin film transistors.

10. The touch panel system of claim 9, wherein at least one of the thin film transistors comprises:

a gate that is reflective to infrared radiation; and

a film that absorbs infrared radiation directed by the at least one infrared source towards and through the touchable surface which is reflected from above the touchable surface by the one or more objects and absorbs infrared radiation which is reflected from below the film by the gate.

11. The touch panel system of claim 10, wherein the film comprises a semiconductor material selected from the group consisting of:

mono-crystalline silicon, polycrystalline silicon, microcrystalline silicon, and nanocrystalline silicon.

12. The touch panel system of claim 10, wherein the film comprises a non-silicon-based semiconductor material.

13. The touch panel system of claim 1, wherein the infrared sensors comprise photodiodes.

14. The touch panel system of claim 1, wherein the display comprises infrared-transmitting and visible-light absorbing filters between the touchable surface and the infrared sensors for shielding the infrared sensors from visible light when detecting the infrared radiation which is reflected from above the touchable surface by the one or more objects.

15. The touch panel system of claim 14, wherein the filter comprises an infrared-transmitting polymer black matrix.

16. The touch panel system of claim 14, wherein the filter comprises a red color filter overlapping a blue color filter.

17. The touch panel system of claim 1, wherein touch panel system is configured to identify locations of different objects that are in contact with the touchable surface, distinguish between the different objects, and alter the image visibly displayed on the display of the touch panel system based on the locations of the different objects.

19. The touch panel of claim 16, wherein the touch panel is implemented by a liquid crystal display.

20. The touch panel of claim 16, wherein the touch panel is implemented by an organic light emitting diode display.

22. The method of claim 19, further comprising:

identifying locations of different objects that are in contact with the touchable surface;

distinguishing between the objects; and

altering the image based on the locations of the different objects.

18. A touch panel having a touchable surface configured to display an image, the touch panel comprising:

a plurality of infrared sources configured to direct infrared radiation towards and through the touchable surface for illuminating one or more objects that are in contact with or adjacent to the touchable surface with infrared radiation;

infrared sensors distributed parallel to the touchable surface, wherein output from a plurality of the infrared sensors is processed to detect an infrared image based on infrared radiation incident on the infrared sensors which is directed by the infrared sources towards and through the touchable surface and reflected from above the touchable surface by the one or more objects; and

a plurality of infrared-transmitting and visible-light absorbing filters between the touchable surface and the infrared sensors, wherein the infrared-transmitting and visible-light absorbing filters shield the infrared sensors from visible light when detecting the infrared radiation which is reflected from above the touchable surface by the one or more objects.

21. A method performed in a touch panel system, the method comprising:

displaying an image viewable via a touchable surface of the touch panel system;

directing infrared radiation from at least one infrared source integrated in the touch panel system towards and through a touchable surface of the touch panel system for illuminating one or more objects that are in contact with or adjacent to the touchable surface with infrared radiation;

detecting infrared radiation incident on infrared sensors which are distributed throughout a touch panel parallel to the touchable surface, wherein the infrared radiation incident on the infrared sensors is directed by the at least one infrared source towards and through the touchable surface and reflected from above the touchable surface by the one or more objects; and

processing output from a plurality of the infrared sensors to detect an infrared image, wherein detection of the infrared image based on the output of the plurality of infrared sensors does not conflict with the image visibly displayed on the display of the touch panel system.