Apple Files Patent For "Active Stylus" For Use With Capacitive Touchscreens 112
MojoKid writes "Apple may be looking to improve upon the stylus as we know it today. The Cupertino company filed a patent application with the USPTO for what it calls an 'Active Stylus,' which can be used on capacitive touch sensor panels like those found on the iPhone, iPad, and iPod Touch devices. 'Unlike conventional styluses which work passively by blocking electric field lines between the drive and sense electrodes of a capacitive touch sensor panel, the styluses disclosed in the various embodiments of this disclosure can either act as a drive electrode to create an electric field between the drive electrode and the sense lines of a mutual capacitive touch sensor panel, or as a sense electrode for sensing capacitively coupled signals from one or more stimulated drive rows and columns of the touch sensor panel or both.' According to Apple, active styluses allow for more accurate input without driving up cost."
I remember those (Score:3, Interesting)
When my grandparents were alive they had a box with one of those.
It was made for teaching people traffic signs. You put an overlay on it and used the active stylus to touch one of the alternatives and the box would indicate green or red light depending on your answer.
Call me dumb... (Score:3, Interesting)
This reminds me of the old IBM light pens of yore... I really don't see much difference between this and those, or the wired pens that were used on old Gridpads in the early 1990s.
What is old is new again, I guess.
There's a claim in there about IQ Mod/Demod (Score:2, Interesting)
In a third embodiment, in-phase/quadrature (IQ) demodulation at the sensor can be performed to circumvent the synchronization issue in a touch sensitive system where the stylus can act as a drive electrode. FIG. 6 illustrates exemplary sense circuitry 610. The sense circuitry 610 can sense a capacitance from conductive elements of a touch sensor panel that are capacitively coupled to the stylus. The stylus sensing circuitry 610 can include amplifier 670 to receive the capacitance reading from the panel, clock 640 to generate a demodulation signal, phase shifter 645 to generate a phase-shifted demodulation signal, mixer 633 to demodulate the capacitance reading with an in-phase demodulation frequency component, and mixer 687 to demodulate the capacitance reading with a quadrature demodulation frequency component. The demodulated results (i.e., the in-phase component 643 and the quadrature component 697) can then be used to determine an amplitude proportional to the capacitance. Essentially, IQ demodulation can eliminate the need to phase-synchronize the drive signal from the stylus and the output signal from the touch sensor panel. However, frequency matching may still be required in this embodiment so that the stylus can be driving at the same frequency at which the touch sensor panel is listening.
Did they really just sneak a claim for IQ mod/demod in there? Something just about every single SDR uses and I'm sure plenty of other active receiver transmitter architectures use.
Do those require power? (Score:4, Interesting)
One of the nice things about the Wacom tablets (typing this while looking into a 21" Wacom Cintiq) is that the stylus doesn't require any power. A quick glance at the patent application above has me seeing "power source" in the pen. I'm not that enthused.
I realise my Cintiq is damned expensive so the criticism above might not apply fully, but I don't feel I'm losing out on accuracy with my non-"Active Stylus" device.
Re:Call me dumb... (Score:1, Interesting)
I know for a fact that the more significant motor industry inventions are patented. That's why there are more than three different implementations of each of variable valve timing and variable valve lift. Honda's VVTL mechanism is simplest and oldest, combining timing and lift adjustment in one mechanism, the others add lift adjusters onto existing VVT systems.
Re:Call me dumb... (Score:4, Interesting)
So it is either too specific to be worth anything (since there are already lots of capacitative styli available for phones and tablets) or the patent office granted yet another overly broad patent on something that was invented years ago.
Either way we lose.
Re:Call me dumb... (Score:4, Interesting)
you can't patent an idea
That's the theory, but it doesn't seem to be enforced much.