Low Profile Touch Panel Systems

• US 20090058832A1
• Filed: 08/29/2008
• Published: 03/05/2009
• Est. Priority Date: 08/30/2007
• Status: Active Grant

• Current Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Next Holdings Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Newton, John
• Granted Patent: US 8,384,693 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A low profile touch display can be provided, namely one including an optical detection system with the bulk of the electronics and optics positioned partially or completely below the detecting plane surface. The light source and optical detection system components can be configured so that the exit and entry apertures for light being directed to and/or received from the detection plane are the only members above the touch surface. For instance, a reflective or refractive member at the edge of the touch surface can direct light to detection optics and/or from illumination sources via a pinhole aperture, with the light moving between the detection optics and illumination sources in one or more detection planes above the touch surface. Consequently, the touch screen can have a thin cross section that is more suitable for devices such as mobile phones, PDAs, and other portable computing devices for which minimal device thickness is a priority.

Claims

1. A touch detection system comprising:

an optical detection system positioned at an edge of a touch surface and positioned at least partially below a plane of the touch surface, the plane of the touch surface corresponding to the top of the touch surface; and

an optical assembly positioned at an edge of the touch surface and extending above the plane of the touch surface so as to intersect with a detection plane above the plane of the touch surface, the optical assembly configured to refract light from an optical path in the detection plane into the optical detection system via a pinhole aperture;

wherein the optical assembly defines a profile height above the plane of the touch surface, the profile height approximately equal to the diameter of the pinhole aperture.

2. The touch detection system set forth in claim 1, wherein the profile height is equal to the diameter of the pinhole aperture.

3. The touch detection system set forth in claim 1, wherein the profile height is less than 1 mm.

4. The touch detection system set forth in claim 3, wherein the pinhole aperture diameter is less than or equal to 0.5 mm.

5. The touch detection system set forth in claim 1, further comprising:

an illumination source positioned at least partially below the plane of the touch surface and configured to direct light toward the optical assembly through the pinhole aperture; and

an illuminated bezel at an edge of the touch surface, the illuminated bezel comprising a surface that reflects light traveling towards the bezel in the detection plane back into the detection plane.

6. The touch detection system set forth in claim 1, further comprising:

an illumination source positioned at least partially below the plane of the touch surface; and

an illuminated bezel at an edge of the touch surface, the illuminated bezel comprising a second optical assembly positioned at an edge of the touch surface and extending above the plane of the touch surface so as to intersect with the detection plane;

wherein the illumination source is configured to direct light toward the second optical assembly and the second optical assembly is configured to refract light received from the illumination source into the optical path lying in the detection plane.

7. The touch detection system set forth in claim 6, wherein the second optical assembly defines a profile height approximately equal to the size of the pinhole aperture.

8. The touch detection system set forth in claim 1, further comprising:

at least a second optical detection system, the second optical detection system positioned an edge of the touch surface and configured to receive light directed toward the second detection system via a pinhole aperture; and

at least one computing device interfaced with the first and second optical detection systems and configured to determine a location at which an object has intersected the detection plane based on data collected from the optical detection systems.

9. The touch detection system set forth in claim 1, further comprising a display system having a top surface positioned parallel to or corresponding to the touch surface.

10. The touch detection system set forth in claim 1, wherein the detection system is positioned completely below the plane of the touch surface.

11. A touch detection system comprising:

an illuminated bezel positioned at an edge of a touch surface and configured to direct light along an optical path laying in a detection plane above a plane of the touch surface, the plane of the touch surface corresponding to the top of the touch surface;

a plurality of detection systems positioned along an edge of the touch surface and positioned at least partially below the plane of the touch surface; and

at least one optical assembly positioned at an edge of the touch surface and extending above the plane of the touch surface so as to intersect with the detection plane, the optical assembly configured to direct light from an optical path laying in the detection plane into the respective detection systems via a pinhole aperture corresponding to each detection system;

wherein the optical assembly extends above the touch surface by a height approximately equal to the diameter of the pinhole apertures.

12. The touch detection system set forth in claim 11,

further comprising an illumination source positioned at least partially below the touch surface and configured to direct light toward the optical assembly through the pinhole aperture;

and

wherein the illuminated bezel comprises a surface that reflects light traveling towards the bezel in the detection plane back into the detection plane.

13. The touch detection system set forth in claim 11,

further comprising an illumination source positioned at least partially below the plane of the touch surface;

wherein the illuminated bezel comprises a second optical assembly positioned at an edge of the touch surface and extending above the plane of the touch surface so as to intersect with the detection plane; and

wherein the illumination source is configured to direct light toward the second optical assembly and the second optical assembly is configured to direct light received from the illumination source into the optical path lying in the detection plane.

14. The touch detection system set forth in claim 11, wherein the diameter of each pinhole aperture is less than or equal to 0.5 mm.

15. The touch detection system set forth in claim 11, further comprising:

at least one computing device interfaced with the detection systems and configured to determine a location at which an object has intersected the detection plane based on data collected from the detection systems.

16. The touch detection system set forth in claim 15, further comprising a display system having a surface positioned parallel to or corresponding to the touch surface, the display system interfaced with the at least one computing device.

17. A touch-enabled display device, comprising:

a display screen having a surface and an area;

a detection system, with at least a portion of the detection system positioned vertically below the screen surface;

an illumination system, with at least a portion of the illumination system positioned vertically below the screen surface;

a computing device configured to determine the location at which an object has changed the transmission of light across a touch area, the touch area being coextensive with at least a part of the area of the display screen; and

at least one optical assembly positioned along at least one edge of the screen, the optical assembly comprising a first facet that faces toward the interior of the touch area and a second facet that does not face toward the interior of the touch area;

wherein the at least one optical assembly is configured so that light entering the assembly at the first facet is directed to exit the optical assembly at the second facet and light entering the optical assembly at the second facet is directed to exit the optical assembly at the first facet; and

wherein the display device is configured so that light is emitted from the illumination system and is directed into the second facet of the optical assembly before crossing the touch area.

18. The touch-enabled display device set forth in claim 17, wherein the display device is configured so that:

the illumination system and detection system are separate from one another; and

light is emitted from the illumination system into a first optical assembly, crosses the touch area, and enters a second optical assembly which directs the light into the detection system via a pinhole aperture.

19. The touch-enabled display device set forth in claim 17, wherein the optical assembly is configured to direct light by reflection.

20. The touch-enabled display device set forth in claim 17, wherein the optical assembly is configured to direct light by refracting light at the first facet.

21. The touch-enabled display device set forth in claim 17, wherein the optical assembly at is configured so that:

light traveling in an optical path in a plane parallel to the plane of the touch surface and intersecting with the first facet is directed by the optical assembly to travel in an optical path in a plane that is not parallel to the plane of the touch surface and intersecting with the second facet.