Transparent digitiser

• US 20080023232A1
• Filed: 10/02/2007
• Published: 01/31/2008
• Est. Priority Date: 08/29/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: Perski, Haim, Morag, Meir
• Granted Patent: US 8,217,918 B2
• Time in Patent Office: Days
• US Class Current: 178/19.01
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A digitizer for user interaction via an object with an electronically refreshable display screen, the digitizer comprising: a transparent sensing arrangement of detectors located at said electronically refreshable display screen for detecting an electric field of said object, said detectors having outputs, and an arrangement of differential amplifiers associated with said outputs, thereby to apply differential detection between said outputs.

Claims

1. A passive stylus for use with a digitizer, comprising:

an outer stylus shaped housing having a front tip,

a resonator arrangement having a predetermined resonant frequency, and

a gap at said tip across which said resonator arrangement is coupled, to create an electric field concentration in the vicinity of said front tip.

2. The passive stylus of claim 1, further comprising a ferrite coil.

3. The passive stylus of claim 1, wherein said resonator is remotely located from said tip and coupled thereto via a conductor.

4. The passive stylus of claim 1, further comprising switchable components to contribute to said resonator arrangement to modify said predetermined resonant frequency to indicate different mode settings of said stylus.

5. The passive stylus of claim 1, further comprising a modulator for providing detectable variations in said electric field according to different mode settings of said stylus.

6. The passive stylus of claim 1, comprising a reverse tip located at a second end remote from said front tip, a conductor arrangement extending to said reverse tip.

7. The passive stylus of claim 6, wherein the geometry in the vicinity of said reverse tip is different from the geometry in the field of said front tip, thereby to provide a detectable difference between said front and reverse tips.

8. The passive stylus of claim 6, further comprising switchable components associated with said reverse tip, to contribute to said resonator arrangement to modify said predetermined resonant frequency to indicate different mode settings of said stylus.

9. The passive stylus of claim 5, wherein said detectable variations are variable delays in coupling of said electric field to said gap.

10. The passive stylus of claim 5, further comprising a normally closed switch associated with said front tip.