Device having touch sensitivity functionality

• US 20030160155A1
• Filed: 10/04/2002
• Published: 08/28/2003
• Est. Priority Date: 10/09/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Liess, Martin Dieter
• Granted Patent: US 6,816,537 B2
• Time in Patent Office: Days
• US Class Current: 250/221
• CPC Class Codes: G06F 3/0423 using sweeping light beams, e.g. using rotating or vibrating mirror

Abstract

The invention relates to a device having touch sensitivity functionality, comprising a surface (2), touch-sensitive means (5) for detecting the presence of a touch input member (6) being in contact with or close to the surface (2) generating a distance sensor signal. Since conventional resistive or capacitive touch-sensitive layers have a limited transparency, they significantly reduce the screen quality. According to the invention, a display device having touch sensitivity functionality is provided without adding a layer to the display, and is characterized in that the touch-sensitive means (5) comprises means (51) for emitting a laser beam (4, 8) in a plane parallel and close to the surface (2), said laser beam being periodically deflected across the entire surface (2), and means (51, 60) for receiving the light reflected or scattered from the touch input member (6) generating said distance sensor signal therefrom.

Claims

1. A device having touch sensitivity functionality, comprising a surface (2), touch-sensitive means (5) for detecting the presence of a touch input member (6) being in contact with or close to the surface (2) generating a distance sensor signal, characterized in that the touch-sensitive means (5) comprises means (51) for emitting a laser beam (4, 8) in a plane parallel and close to the surface (2), said laser beam being periodically deflected across the entire surface (2), and means (51, 60) for receiving the light reflected or scattered from the touch input member (6) generating said distance sensor signal therefrom.

2. A device according to claim 1, characterized in that signal-processing means (57) are provided for determining the position of the touch input member (6) being in contact with or close to surface (2) from said distance sensor signal.

3. A display device according to claim 2, characterized in that said distance sensor signal includes information about the distance between the means (51) for emitting said laser beam and the direction of reflection, and that the signal-processing means (57) are adapted to calculate the position of the touch input member from said distance and the angle of emission of the laser beam.

4. A device according to claim 1, characterized in that the touch-sensitive means (5) includes a laser diode (51) and a photodiode (60).

5. A device according to claim 4, characterized in that the laser diode (51) is commonly used for emitting and detecting the laser beam, and that the light emitted from the laser diode (51) is scattered back into the laser diode (51), thus modulating the emitted laser beam (4).

6. A device according to claim 1, characterized in that the means (51) for emitting the laser beam and the means for receiving the light are positioned within the frame (3) of the surface (2), particularly in one corner of the frame (3).

7. A device according to claim 1, characterized in that the means (51) for emitting the laser beam is positioned to emit the laser beam in a plane directly above the surface (2).

8. A device according to claim 1, characterized in that the means (51, 60) for receiving the light are adapted to receive light reflected or scattered from the frame (3) of the surface or from the touch input member (6) generating said distance sensor signal therefrom.

9. A device according to claim 1, characterized in that the frame (3) of the surface (2) comprises laser reflection means for reflecting the laser beam (4) positioned in such a way that the laser beam (4) is reflected into the means (51, 60) for receiving the light.

10. A device according to claim 1, characterized in that the touch-sensitive means (5) comprises oscillating means (54, 55) for reflecting the laser beam (4) periodically across the entire surface (2) by periodically changing the orientation of a mirror (53) for deflecting the laser beam (4).

11. A device according to claim 10, characterized in that the oscillating means (54, 55) comprises an electronically driven mechanical oscillator.

12. A touch sensitivity display device comprising a device as claimed in claim 1, wherein the surface (2) is a display or a screen.

13. A keyboard comprising a device as claimed in claim 1, wherein the surface (2) is marked with numbers and/or characters.

14. A method of sensing a touch of a surface (2) by a touch input member in a device having touch sensitivity functionality, comprising a surface (2), touch-sensitive means (5) for detecting the presence of a touch input member (6) being in contact with or close to the surface (2) generating a distance sensor signal, characterized in that a laser beam (4, 8) is emitted in a plane parallel and close to the surface (2), in that the laser beam is periodically deflected across the entire surface (2) and in that the light reflected or scattered from the frame (3) of the surface (2) or from the touch input member (6) is received and said distance sensor signal is generated therefrom.