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Tablet pen, how do they work?

Last response: in Laptops & Notebooks
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Anonymous
a b D Laptop
August 16, 2004 2:38:38 PM

Archived from groups: comp.sys.laptops (More info?)

Hi, how does a tablet pen/pointer work? I have extra tips and tried using an
extra tip as my stylus for both my PDA and tablet, but it appears not to work
at all with the tablet even though the regular stylus for the tablet works
okay. Does the tip need to be in the stylus? How does this work?

Thanks,

Tim Lange
West Lafayette, IN

More about : tablet pen work

Anonymous
a b D Laptop
August 16, 2004 9:32:00 PM

Archived from groups: comp.sys.laptops (More info?)

Timothy Lange wrote:
> Hi, how does a tablet pen/pointer work? I have extra tips and tried
> using an extra tip as my stylus for both my PDA and tablet, but it
> appears not to work at all with the tablet even though the regular
> stylus for the tablet works okay. Does the tip need to be in the
> stylus? How does this work?

There are electronics inside the stylus.

The tablet emits magnetic pulses that are picked up by an inductive coil
inside the stylus. Early styli used a battery. Nowadays the magnetic
pulses are cleverly used not only for position sensing by the pad, but also
to power the switches and pressure sensor in the stylus.

The stylus tip physically connects to a pressure sensor but has no
electronic functionality, which is why nothing happens when you write with
it.

PDA's almost always have all their electronics in the device and use a non
electronic pointer.
--

Mike Russell
www.curvemeister.com
www.geigy.2y.net
Anonymous
a b D Laptop
August 16, 2004 9:32:01 PM

Archived from groups: comp.sys.laptops (More info?)

Expanding on the various touchscreen technologies that can be used for
Touch Tablets (not all are used today with the pen & tablet design often
seen with current Tablet PCs):

What types of touchscreen technologies are there?
There are several types of touchscreens manufactured. Each has their
pluses and minuses. These are the four most common:


Analog Resistive
Capacitive
Acoustic Wave
Electromechanical


Analog Resistive
Analog resistive is the most popular and stable of all the technologies.
It is the basis of our TouchSTAR PSR1 technology. An analog resistive
screen converts the analogy of putting pressure on the screen into the
equivalent of clicking with a mouse. The pressure point on the screen’s
surface determines where in the horizontal (X) and vertical (Y) axes the
computer relates the click event. Analog resistive touchscreen displays
require the installation of a multilayer overlay to the screen. This
overlay is connected to a controller that converts the analog
information into digital information. This controller is then connected
to your computer using serial or USB connections.

Capacitive
Capacitive touchscreens also require an overlay and controller. The
overlay typically uses fine wires to make the grid across the screen.
Capacitive touchscreens don’t require pressure to function. They
determine their X & Y location by calculating the change in electrical
capacitance. Typically this occurs with a touch of a bare finger on or
near the screen’s surface which slightly drains the electric energy
where touched and this change in capacitance can be calculated into an
X-Y location. Capacitive screens do not have the highest resolutions and
typically have issues with drift of the calibration. They cannot be used
with a glove hand or a stylus.

Acoustic Wave
Acoustic wave technology places transducers (like tiny microphones) on
the corners of your display. The controller sends an inaudible sound
wave continuously through the transducers to make a cross hatch pattern
over the screen. As an object blocks the sound wave a touch is detected
and that determines where the X-Y click should be. While this technology
does not put an overlay on the display, the transducers are quite
fragile and dirt or moisture on the screen will impact its performance.

Electromechanical
Using a combination of electrical components and a mechanical components
(often embedded into a proprietary pen type stylus), the
electromechanical touchscreen is not affected by multiple simultaneous
touches and so it is ideal for drawing while resting your hand on the
screen. Electromechanical touchscreens can account for variation
pressure, pen tilt and other attributes that other touchscreens cannot.
But they also cannot be used with a finger or generic stylus.
!