OPTICAL TOUCH SCREEN SYSTEMS USING REFLECTED LIGHT

• US 20100238138A1
• Filed: 04/15/2010
• Published: 09/23/2010
• Est. Priority Date: 02/15/2009
• Status: Active Grant

• Current Assignee: Neonode, Inc.
• Original Assignee: Neonode, Inc.
• Inventors: Shain, Joseph, Goertz, Magnus, Eriksson, Thomas
• Granted Patent: US 9,213,443 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• 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: 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
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421

Abstract

A touch screen system, including a near-infrared transparent screen including a plurality of reflective elements embedded therein, a circuit board including circuitry for controlled selective activation of electronic components connected thereto, at least one light source connected to the circuit board, for emitting light, and at least one light detector connected to the circuit board, for detecting light emitted by the at least one light source and reflected by the reflective elements.

Claims

1. A touch screen system, comprising:

a near-infrared transparent screen comprising a plurality of reflective elements embedded therein;

a circuit board comprising circuitry for controlled selective activation of electronic components connected thereto;

at least one light source connected to said circuit board, for emitting light; and

at least one light detector connected to said circuit board, for detecting light emitted by said at least one light source and reflected by said reflective elements.

2. The touch screen system of claim 1 further comprising at least one optical element for guiding light emitted by said at least one light source towards said reflective elements.

3. The touch screen system of claim 2 wherein said plurality of optical elements comprises fibers.

4. The touch screen system of claim 2 wherein said plurality of optical elements comprises elliptical mirrors.

5. The touch screen system of claim 2 wherein said plurality of optical elements comprise filament light guides.

6. The touch screen system of claim 2 wherein said plurality of optical elements comprises wedge-shaped plates.

7. The touch screen system of claim 2 wherein said plurality of optical elements comprise planar plates positioned parallel to said near-infrared transparent screen.

8. The touch screen system of claim 1 wherein said at least one light detector comprises at least one camera.

9. The touch screen system of claim 1 wherein said at least one light detector comprises at least one photo detector.

10. The touch screen system of claim 1 wherein said at least one light source is placed underneath said near-infrared transparent screen.

11. The touch screen system of claim 1 wherein said at least one light detector is placed underneath said near-infrared transparent screen.

12. The touch screen system of claim 1 wherein said near-infrared transparent screen comprises at least two layers, wherein said at least one light source emits light in a first layer and said at least one light detector detects light transmitted in a second layer.

13. A touch screen system comprising:

a display screen;

a circuit board comprising circuitry for controlled selective activation of electronic components connected thereto;

a plurality of near-infrared LEDs connected to said circuit board, for emitting light;

a first plurality of photo diodes connected to said circuit board, for detecting received light along a first edge of said display screen; and

a second plurality of photo diodes connected to said circuit board, for detecting received light along a second edge of said display screen,

wherein said circuitry generates signals responsive to blocked light from said near-infrared LEDs detected at said first plurality of photo diodes and signals responsive to reflected light from said near-infrared LEDs detected at said second plurality of photo diodes.

14. The touch screen system of claim 13 wherein said circuitry calculates a position of a pointer that touches said display screen, based on the signals for the blocked light and the signals for the reflected light signals.

15. The touch screen system of claim 13 further comprising at least one optical element for guiding light emitted by said near-infrared NIRs over said touch screen.

16. The touch screen system of claim 13 wherein said near-infrared LEDs are embedded within said display screen.

17. The touch screen system of claim 13 wherein said display screen comprises a plurality of reflective elements embedded therein, which reflect light emitted by said near-infrared LEDs.

18. The touch screen system of claim 13 wherein said first plurality of photo diodes are embedded within said display screen.

19. The touch screen system of claim 13 wherein said second plurality of photo diodes are embedded within said display screen.

20. A touch screen system comprising:

a display screen comprising a plurality of layers substantially parallel to one another;

a circuit board comprising circuitry for controlled selective activation of electronic components connected thereto;

a plurality of near-infrared LEDs connected to said circuit board, for emitting light that is guided through a first layer of said display screen; and

a plurality of photo diodes connected to said circuit board, for receiving light that is guided through a second layer of said display screen,

wherein said circuitry generates signals responsive to light detected at said plurality of photo diodes.