Integrated light guide and touch screen frame and multi-touch determination method

• US 9,207,800 B1
• Filed: 01/02/2015
• Issued: 12/08/2015
• Est. Priority Date: 09/23/2014
• Status: Active Grant

• Current Assignee: Neonode, Inc.
• Original Assignee: Neonode, Inc.
• Inventors: Eriksson, Thomas, Jubner, Alexander, Karlsson, John, Sparf, Lars, Lindfors, Saska, Pettersson, Robert
• Primary Examiner(s): Giesy, Adam R
• Application Number:
  US14/588,462
• Time in Patent Office: 340 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A touch screen assembly including a glass screen, LEDs, photo diodes, a transparent plastic frame surrounding the screen, and a light guide that guides light emitted by the LEDs to the photo diodes along light paths that go under the frame on one side, over the screen, and under the frame on the opposite side, and a processor operative to selectively activate LEDs and photo diodes, to identify location of an object touching the screen, based on amounts of light detected by activated photo diodes when light emitted by activated LEDs is blocked along its light path by the object, and to recognize the object touching the frame, based on amounts of light detected by activated photo diodes when light emitted by activated LEDs is absorbed along its light path by the object, thereby providing light-based touch sensitivity to the screen and to the frame.

Claims

1. A touch screen assembly, comprising:

a curved display screen;

a plurality of light emitters, mounted underneath said display screen, operative to emit light when activated;

a plurality of photo diodes, mounted underneath said display screen, operative to detect amounts of light received when activated;

a frame comprising internally reflective surfaces that guide light emitted by said light emitters along light paths that travel upwards, above and across said display screen in segments that follow the contour of said display screen, and downwards to said photo diodes, wherein the frame is oriented such that some of the light paths are incident upon and reflect off of said display screen while crossing said display screen; and

a processor coupled with said light emitters and said photo diodes, operative to selectively activate said light emitters and said photo diodes, and to identify a location of an object touching said display screen, based on amounts of light detected by activated photo diodes when light emitted by activated light emitters is blocked by the object along its light path.

2. The touch screen assembly of claim 1 wherein said curved display screen has a curved contour cross-section in one direction and a straight contour cross-section in another direction.

3. The touch screen assembly of claim 1 wherein said curved display screen is approximately 34″

from corner-to-corner diagonally.

4. The touch screen assembly of claim 1 wherein said frame further comprises:

an exposed upper edge along the entire frame perimeter; and

vertically straight inner walls, extending from below said display screen to said exposed upper edge of the frame, along the entire frame perimeter.

5. The touch screen assembly of claim 1 whereby said display screen has neither stiffeners nor support elements at its upper surface.

6. The touch screen assembly of claim 1 further comprising:

a floor dividing said frame into an upper cavity that houses said display screen, and a lower cavity; and

PCB strips, housed in the lower cavity, on which said light emitters and said photo diodes are mounted.

7. The touch screen assembly of claim 1 wherein said processor recognizes the object touching outer walls of said frame based on amounts of light detected by activated photo diodes when light emitted by activated light emitters is absorbed along its light path by the object at the outer walls, thereby providing light-based touch sensitivity to said frame.

8. The touch screen assembly of claim 7 further comprising visible-light LEDs mounted underneath said frame, which are illuminated by said processor in response to recognizing the object touching the outer walls of said frame.

9. The touch screen assembly of claim 7 wherein said processor opens a user interface bar in response to recognizing the object touching the outer walls of said frame.

10. The touch screen assembly of claim 1 further comprising visible-light LEDs mounted underneath said frame, which are illuminated by said processor to match the illumination of said display screen at its outer edges, thereby giving an appearance that the image displayed on said display screen extends to said frame.

11. The touch screen assembly of claim 1 further comprising:

a network adaptor connected to said processor; and

visible-light LEDs mounted underneath said frame,

wherein said processor illuminates said visible-light LEDs in response to said network adaptor receiving a communication.