Transparent digitiser
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.
1. A passive stylus for use with a digitizer, comprising:
an outer stylus shaped front housing having a front tip,
a corresponding reverse tip, the reverse tip located at a second end of the stylus remote from said front tip,
a resonator arrangement electrically connected at one end to both the front tip and the reverse tip and at another end to both the front housing and the rear housing, the resonator arrangement having a resonant frequency, and
a first gap formed between the front housing and the front tip across which said resonator arrangement is coupled, to create a first electric field concentration in a vicinity of said front tip,
a second gap formed between the rear housing and the reverse tip across which said resonator arrangement is coupled, to create a second electric field concentration in a vicinity of said rear 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 at least one of said front tip and said reverse 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 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 first electric field according to different mode settings of said stylus.
6. The passive stylus of claim 5 , wherein said detectable variations are variable delays in coupling of said electric field to said first gap.
7. The passive stylus of claim 6 , wherein the different mode settings of said stylus is selected from a group including at least one of right click, left click, hover and erase.
8. The passive stylus of claim 5 , further comprising a normally closed switch associated with said front tip.
9. The passive stylus of claim 1 , further comprising switchable components associated with said reverse tip, to contribute to said resonator arrangement to modify said resonant frequency to indicate different mode settings of said stylus.
10. The passive stylus of claim 1 , wherein a portion of each of the front tip, the reverse tip, the rear housing and the front housing electrically connected to the resonator arrangement is formed from a conductive material.
11. The passive stylus of claim 1 , wherein the resonator arrangement has a predetermined resonant frequency.
12. A passive stylus for use with a digitizer, comprising:
an outer stylus shaped housing having a front tip,
a resonator arrangement electrically connected at one end to the front tip and at another end to the housing, the resonator arrangement having a resonant frequency,
a gap formed between the housing and the front tip across which said resonator arrangement is coupled, to create an electric field concentration in a vicinity of said front tip, and
a reverse tip located at a second end of the stylus remote from said front tip, a conductor arrangement extending to said reverse tip, wherein a geometry of the gap in the vicinity of said reverse tip is defined to be different from the geometry of the gap in the vicinity of said front tip, thereby to provide a detectable difference between output from said front and reverse tips.
13. The passive stylus of claim 12 , further comprising switchable components to contribute to said resonator arrangement to modify said resonant frequency to indicate different mode settings of said stylus.
14. A passive stylus for use with a digitizer, comprising:
an outer stylus shaped housing having a front tip,
a resonator arrangement electrically connected at one end to the front tip and at another end to the housing, the resonator arrangement having a resonant frequency,
a gap formed between the housing and the front tip across which said resonator arrangement is coupled, to create an electric field concentration in a vicinity of said front tip, and
a reverse tip located at a second end of the stylus remote from said front tip, a conductor arrangement extending to said reverse tip, wherein a size of an electric field concentration of said reverse tip is defined to be larger than a size of the electric field concentration of said front tip, thereby to provide a detectable difference between said electric field concentration from the front and reverse tips.
15. The passive stylus of claim 14 , further comprising switchable components to contribute to said resonator arrangement to modify said resonant frequency to indicate different mode settings of said stylus.