Infrared sensor integrated in a touch panel

• US 8,411,070 B2
• Filed: 03/11/2011
• Issued: 04/02/2013
• Est. Priority Date: 11/27/2006
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Boer, Willem den, Bathiche, Steven N., Hodges, Stephen Edward, Izadi, Shahram
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Hegarty, Kelly B
• Application Number:
  US13/046,481
• Publication Number:
  US 20110169779A1
• Time in Patent Office: 753 Days
• Field of Search: 345156-158, 345/173, 345/175, 345/176, 345/76, 345/211, 345/207, 715/702, 715/740, 178 1801- 1904, 434322-364, 315149-150, 713300-320, 713323-340
• 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 touchable surface;

at least one infrared source integrated in the touch panel system and configured to direct infrared radiation 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 display configured to illuminate pixels for visibly displaying an image, the touch panel display comprising;

a matrix circuit including pixel circuit elements;

infrared sensors that are integrated in the matrix circuit with the circuit elements and distributed parallel to the touchable surface, wherein;

the infrared sensors are configured to detect reflected infrared radiation incident on the infrared sensors,

infrared radiation directed by the at least one infrared source through the touchable surface is not detected by the infrared sensors,

reflected infrared radiation directed through the touchable surface by the one or more objects is detected by the infrared sensors,

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 touch panel display of the touch panel system; and

infrared-transmitting and visible-light absorbing filters between the touchable surface and the infrared sensors, each infrared-transmitting and visible-light absorbing filter comprising overlapping complementary color filters, wherein the infrared-transmitting and visible-light absorbing filters shield the infrared sensors from visible light when detecting the reflected infrared radiation directed through the touchable surface by the one or more objects.

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

a backlight arranged below the touch panel display, 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 touch panel display is a liquid crystal display.

5. The touch panel system of claim 4, wherein the matrix circuit is included in 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 touch panel 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 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 film that absorbs reflected infrared radiation directed through the touchable surface by the one or more objects.

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 overlapping complementary color filters comprise a red color filter overlapping a blue color filter.

15. 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 by processing reflected infrared radiation which is directed through the touchable surface by the different objects and detected by the infrared sensors, and

alter the image visibly displayed on the display of the touch panel system based on the locations of the different objects.

16. A touch panel display comprising:

a touchable surface;

a plurality of pixels for visibly displaying an image on the touchable surface;

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

a backplane including pixel circuit elements;

infrared sensors that are integrated in the backplane with the pixel circuit elements and distributed parallel to the touchable surface, wherein;

output from a plurality of the infrared sensors is processed to detect an infrared image based on reflected infrared radiation incident on the infrared sensors,

infrared radiation directed by the infrared sources through the touchable surface is not detected by the infrared sensors, and

reflected infrared radiation directed through the touchable surface by the one or more objects is detected by the infrared sensors; and

a plurality of infrared-transmitting and visible-light absorbing filters between the touchable surface and the infrared sensors, each infrared-transmitting and visible-light absorbing filter comprising overlapping complementary color filters, wherein the infrared-transmitting and visible-light absorbing filters shield the infrared sensors from visible light when detecting the reflected infrared radiation directed through the touchable surface by the one or more objects.

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

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

19. The touch panel display of claim 16, wherein the overlapping color filters comprise a red color filter overlapping a blue color filter.

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

visibly displaying an image on a touchable surface of a touch panel display by illuminating pixels of the touch panel display;

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

detecting reflected infrared radiation incident on infrared sensors which are integrated in the touch panel display with pixel circuit elements and distributed parallel to the touchable surface, wherein;

the infrared radiation directed by the at least one infrared source through the touchable surface is not detected by the infrared sensors,

reflected infrared radiation directed through the touchable surface by the one or more objects is detected by the infrared sensors, and

the touch panel display includes infrared-transmitting and visible-light absorbing filters between the touchable surface and the infrared sensors, each infrared-transmitting and visible-light absorbing filter comprising overlapping complementary color filters, wherein the infrared-transmitting and visible-light absorbing filters shield the infrared sensors from visible light when detecting the reflected infrared radiation directed through 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 touch panel display of the touch panel system.

21. The method of claim 20, further comprising:

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

distinguishing between the objects by processing reflected infrared radiation which is directed through the touchable surface by the different objects and detected by the infrared sensors; and

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

22. The method of claim 20, wherein the overlapping color filters comprise a red color filter overlapping a blue color filter.