Uniform illumination of interactive display panel

• US 20070200970A1
• Filed: 02/28/2006
• Published: 08/30/2007
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Keam, Nigel, Bathiche, Steven
• Granted Patent: US 7,515,143 B2
• Time in Patent Office: Days
• US Class Current: 349/58
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

An interactive display device employing a flat panel display (FPD). The interactive display device includes a housing, a flat panel display, a light diffusing layer, a visible light illumination system, and a non-visible light illumination system that is used for detecting objects adjacent to the FPD. Techniques are also described for providing uniform illumination of the FPD with visible light, when viewed from a plurality of viewing angles by a user, and for diffusing the visible illumination at a surface boundary of the FPD, such that a coherent image of an interior of the housing is at least partially obscured from view by the user. Non-visible light that has passed through the FPD is reflected from objects adjacent to the display, passes back through the FPD, and is detected within the housing.

Claims

1. A method for illuminating an interactive display to display images, and for detecting objects that are in contact with or in close proximity to the interactive display, comprising the steps of:

(a) illuminating a first surface of the interactive display with visible light that is substantially uniform when a second surface of the interactive display is viewed by a user from a plurality of substantially different viewing angles, wherein the second surface is opposite the first surface;

(b) diffusing the visible light such that a coherent image of an object below a viewing plane of the interactive display is at least partially obscured from view by the user; and

(c) uniformly illuminating the first surface of the interactive display with non-visible light for use in detecting objects disposed in contact with or adjacent to the second surface of the interactive display and wherein the interactive display is configured to be substantially transparent to the non-visible light.

2. The method of claim 1, wherein the step of illuminating a first surface of the interactive display with visible light comprises directly illuminating of the first surface of the interactive display with an illumination source.

3. The method of claim 1, wherein the step of illuminating a first surface of the interactive display with visible light comprises indirectly illuminating of the first surface of the interactive display with an illumination source coupled to a light guide.

4. The method of claim 1 wherein the step of uniformly illuminating the first surface of the interactive display with non-visible light further comprises detecting non-visible light that has passed from the first surface to the second surface of the interactive display, been reflected from the objects disposed in contact with or adjacent to the second surface and then passed back through the interactive display to the first surface.

5. An interactive display, comprising:

(a) an interactive display housing;

(b) a flat panel display (FPD) configured to display images;

(c) a light diffusing layer;

(d) an illumination system configured to substantially uniformly illuminate the FPD with visible light;

(e) a non-visible light illumination system for illuminating objects adjacent to the FPD with non-visible light that has passed through the FPD; and

(f) a sensor for detecting non-visible light reflected from the objects that are adjacent to the FPD.

6. The interactive display of claim 5, wherein the illumination system comprises at least one visible light illuminant configured to directly illuminate the FPD.

7. The interactive display system of claim 5, wherein the illumination system comprises a main portion within the interactive display housing, including:

(a) a light guiding assembly that includes at least one visible light illuminant;

(b) at least one light diffuser; and

(c) a backplane reflective of visible light.

8. The interactive display system of claim 7, wherein the light diffuser is a Fresnel lens configured to condition visible light emitted from the light guide in order to provide uniform illumination to the FPD.

9. The interactive display system of claim 7, wherein the light guiding assembly comprises:

(a) an acrylic sheet; and

(b) at least one of a fluorescent tube and an LED positioned along an edge of the acrylic sheet such that light emitted from the fluorescent tube is caused to be guided by the acrylic sheet.

10. The interactive display of claim 7, wherein the illumination system is disposed immediately adjacent to the FPD.

11. The interactive display system of claim 7, wherein the illumination system is substantially spaced apart from the FPD.

12. The interactive display system of claim 11, wherein a main portion surface area is substantially greater than an FPD surface area such that illumination of the FPD is substantially uniform when viewed from a plurality of viewing angles by a user.

13. The interactive display system of claim 11, wherein the illumination system further comprises side portions being reflective of visible light and being disposed perpendicular to the main portion and extending from the main portion to the user interface surface thereby forming a closed illumination system with the FPD and the user interface surface such that illumination of the FPD is substantially uniform when viewed from a plurality of viewing angles by a user.

14. The interactive display system of claim 11, wherein the main portion of the illumination system is substantially curvilinear such that a continuous surface is formed extending to the user interface surface from a center point of the main portion thereby forming a closed illumination system with the FPD and user interface surface such that illumination of the FPD is substantially uniform when viewed from a plurality of viewing angles by a user.

15. The interactive display system of claim 10, wherein the illumination system further comprises illuminated side portions disposed substantially perpendicular to the main portion and extending to the user interface surface from the main portion to form a closed illumination system with the FPD such that illumination of the FPD is substantially uniform when viewed from a plurality of viewing angles by a user, wherein the illuminated side portions each comprise an illuminated light guide, at least one light diffuser and a reflective backplane.

16. The interactive display system of claim 5, wherein non-visible light illumination system comprises a plurality of infrared illuminants disposed within the interactive display housing for illuminating the interactive display surface with infrared illumination and wherein the sensor for detecting non-visible light comprises a digital camera sensitive to infrared illumination.

17. An interactive display system, comprising:

(a) an interactive display housing including an interactive display chassis and a user interface surface coupled to the chassis;

(b) a liquid crystal display (LCD) panel coupled to the user interface surface of the interactive display housing;

(c) a light diffusing layer coupled to the LCD panel;

(d) an illumination system disposed within the interactive display housing and configured for substantially uniformly illuminating the LCD panel with visible light; and

(e) a user input detection system for sensing objects disposed adjacent to the user interface surface in response to non-visible light that has passed through the LCD panel, been reflected from the objects, passed back through the LCD panel, and been detected within the interactive display housing.

18. The interactive display of claim 17, wherein the illumination system comprises at least one illuminant configured to directly illuminate the bottom LCD surface of the LCD panel from within the interactive display housing.

19. The interactive display of claim 17, wherein at least a portion of the illumination system is spaced apart from the LCD panel and comprises:

(a) a light guide having an illuminant configured to illuminate at least one edge of the light guide with visible light;

(b) at least one Fresnel lens;

(c) at least one light diffuser; and

(d) a backplane substantially reflective of visible light.

20. The interactive display of claim 17, wherein the illumination system is substantially adjacent and coupled to the LCD panel and comprises:

(a) a light guide having an illuminant configured to illuminate at least one edge of the light guide with visible light;

(b) at least one Fresnel lens;

(c) at least one light diffuser; and

(d) a cold mirror.