ILLUMINATOR FOR TOUCH- AND OBJECT-SENSITIVE DISPLAY

• US 20110043490A1
• Filed: 11/19/2009
• Published: 02/24/2011
• Est. Priority Date: 08/21/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Powell, Karlton, Masalkar, Prafulla, Large, Timothy, Bathiche, Steven
• Granted Patent: US 8,730,212 B2
• Time in Patent Office: Days
• US Class Current: 345/176
• 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
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

An integrated vision and display system comprises a display-image forming layer configured to transmit a display image for viewing through a display surface; an imaging detector configured to image infrared light of a narrow range of angles relative to the display surface normal and including a reflection from one or more objects on or near the display surface; a vision-system emitter configured to emit the infrared light for illuminating the objects; a visible- and infrared-transmissive light guide having opposing upper and/or lower face, configured to receive the infrared light from the vision-system emitter, to conduct the infrared light via TIR from the upper and lower faces, and to project the infrared light onto the objects outside of the narrow range of angles relative to the display surface normal.

Claims

1. An integrated vision and display system comprising:

a display-image forming layer configured to transmit a display image for viewing through a display surface;

an imaging detector configured to image infrared light of a narrow range of angles relative to the display surface normal, the imaged infrared light including a reflection from one or more objects arranged on or near the display surface;

a vision-system emitter configured to emit the infrared light, for illuminating the one or more objects; and

a visible- and infrared-transmissive light guide having opposing upper and lower faces, configured to receive the infrared light from the vision-system emitter, to conduct the infrared light via total internal reflection from the upper and/or lower face, and to project the infrared light onto the one or more objects outside of the narrow range of angles relative to the display surface normal.

2. The system of claim 1, wherein the light guide is layered between the display-image forming layer and the display surface.

3. The system of claim 1, wherein the display-image forming layer is layered between the light guide and the display surface.

4. The system of claim 1, wherein the vision-system emitter comprises a plurality of infrared emitters arranged along one or more edges of the light guide.

5. The system of claim 1, wherein the light guide is wedge-shaped, having opposing first and second edge faces of unequal height adjacent the upper and lower faces, and wherein infrared light from the vision-system emitter is conducted from the first edge face toward the second edge face, meets the upper or lower face at a subcritical incidence angle, and refracts out of the light guide to illuminate the one or more objects.

6. The system of claim 1, wherein the light guide is sheet-like, having opposing first and second edge faces of substantially equal height adjacent the upper and lower faces and a diffusive layer arranged parallel to the upper and lower faces, and wherein infrared light from the vision-system emitter is conducted from the first edge face toward the second, interacts with the diffusive layer, and is diffused out of the light guide to illuminate the one or more objects.

7. The system of claim 6, wherein the diffusive layer comprises a plurality of light-diffusing features distributed on a three-dimensional volume on or within the light guide.

8. The system of claim 6, wherein the diffusive layer comprises a plurality of light-diffusing features arranged in a two-dimensional surface on or within the light guide.

9. The system of claim 6, wherein a light-diffusing strength of the diffusive layer increases with increasing distance from the vision-system emitter.

10. The system of claim 9, wherein the light-diffusing strength increases continuously with increasing distance from the vision system emitter.

11. The system of claim 9, wherein opposing collection optics couple infrared light into opposing edges of the light guide, and wherein a light-diffusing strength of the diffusive layer is weaker nearest the opposing edges and stronger in a middle portion of the light guide.

12. The system of claim 1, wherein the light guide comprises a reflective and transmissive filter layer arranged parallel to the diffusive layer and on a side of the diffusive layer opposite the display surface, wherein the filter layer is more reflective and less transmissive to light of greater incidence angles than to light of lower incidence angles, and wherein the filter layer is more reflective and less transmissive to infrared light than to visible light.

13. The system of claim 12, wherein the filter layer comprises one or more of an interference filter, a dichroic filter, and a rugate filter.

14. The system of claim 1, further comprising a computer configured to send display data to the display-image forming layer and to receive image data from the imaging detector, wherein the computer is responsive to a position of the one or more objects arranged on or near the display surface, and to an increasing or decreasing contact area between the one or more objects and the display surface.

15. An integrated vision and display system comprising:

an LCD layer configured to transmit a display image for viewing through a display surface;

a digital camera configured to image infrared light of a narrow range of angles relative to the display surface normal, the imaged infrared light including a reflection from one or more objects arranged on or near the display surface;

a vision-system emitter configured to emit the infrared light, for illuminating the one or more objects;

a sheet-like, visible- and infrared-transmissive light guide having opposing upper and lower faces, opposing edge faces adjacent the upper and lower faces, and a diffusive layer arranged parallel to the upper and lower faces, the light guide configured to receive the infrared light from the vision-system emitter, to conduct the infrared light from one edge face toward another edge face via total internal reflection from the upper and/or lower face, and to project the infrared light onto the one or more objects outside of the narrow range of angles relative to the display surface normal, by interaction with the diffusive layer; and

at least one collection optic configured to partly converge and couple light from the vision-system emitter into the light guide.

16. The system of claim 15, wherein a light-diffusing strength of the diffusive layer increases with increasing distance from the at least one collection optic.

17. The system of claim 15, wherein the diffusive layer comprises a plurality of light-diffusing features distributed in a three-dimensional volume on or within the light guide.

18. The system of claim 15, wherein the diffusive layer comprises a plurality of light-diffusing features arranged on a two-dimensional surface on or within the light guide.

19. An integrated vision and display system comprising:

an LCD layer configured to transmit a display image for viewing through a display surface;

a digital camera configured to image infrared light of a narrow range of angles relative to the display surface normal, the imaged infrared light including a reflection from one or more objects arranged on or near the display surface;

a vision-system emitter configured to emit the infrared light, for illuminating the one or more objects;

a visible- and infrared-transmissive light guide having opposing upper and lower faces and a filter layer arranged on the lower face, the light guide configured to receive the infrared light from the vision-system emitter, to conduct the infrared light via total internal reflection from the upper and/or lower face, and to project the infrared light onto the one or more objects outside of the narrow range of angles relative to the display surface normal, the filter layer configured to be more reflective and less transmissive to light of greater incidence angles than to light of lower incidence angles, and more reflective and less transmissive to infrared light than to visible light; and

at least one collection optic configured to partly converge and couple light from the vision-system emitter into the light guide.

20. The system of claim 19, wherein the filter layer comprises one or more of an interference filter, a dichroic filter, and a rugate filter.