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design are also required, and it is also neces-
sary to reconsider the usability. This technol-
ogy (still) does not meet the requirements for
safety management in the industry, e.g. imple-
mentation of redundant systems; an errone-
ous activation due to incorrect recognition is
possible. Camera-based recognition of ges-
tures was successfully integrated in gaming
and automotive applications, but the attempt
to introduce hover gestures in the mobile tele-
coms market was less successful.
PCAP with Force or 3D Touch has the great-
est development potential in the industry. The
pursued goal here is to recognize a change
in the Z axis and thus the level of pressure
applied by measuring the surface of the touch
point. The exerted force can also be measured
through additional pressure sensors. With
mobile devices that have thin cover glass in
particular, the surface curvature of the glass is
thus measured. In the case of Force Touch, the
interaction takes place independently of the
pressure applied to the touch surface, which
means that additional possibilities for use are
available on the interface. The classic right
click on the mouse can then potentially take
place by increasing the input pressure. The
redundancy of the signal evaluation is one of
the important details for industrial produc-
tion. This occurs in the case of applications
with Force Touch via touch controllers and
of evaluation electronics such as that of force
sensors. The function of the device can then
be triggered - if desired - when both signals
are registered. This is an essential requirement
in medical applications. This dual channel
redundant touch recognition could be a useful
addition e.g. in intensive care. Especially since
the PCAP operating unit remains insuscepti-
ble to conductive fluids, as it is triggered with-
out additional pressure despite the electrode
short circuits of the touch. Force Touch pro-
vides advantages in the development of indus-
trial PCAP enhancements of added value, so
the Munich-based visual solutions provider
Data Modul is focusing on evaluations with
force sensors which are integrated in the edge
of the touch sensor. Cover glass in the indus-
try is usually too thick for the measurement
of the surface curvature on the touch glass (>
than 2 mm) and high-resolution touch sen-
sors for large diagonals (> 15.6”) are difficult
to create.
An existing package consisting of TFT, touch
glass, cover glass with optical bonding can be
used almost unchanged as a starting basis; the
enhancement with Force Touch takes place on
an additional basis; the industrial customer
does not have to go without the existing bene-
fits of touch technology, such as complete pro-
tective glass. But this enhancement represents
a challenge for existing client applications.
The touch unit provides the touch coordi-
nates plus the force values per coordinate, but
the software must be able to interpret these.
This means: a consideration of the respec-
tive adjustment of the client software and of
the graphic surface (GUI, usability) in prod-
uct development/conversion. Force Touch
systems require proprietary driver solutions.
There are no standardized interfaces so far;
isolated solutions are a valid possibility here.
The bottom line: PCAP Touch technology
has found its way into professional operat-
ing concepts via consumer products. This has
increased user expectations/wishes/require-
ment/demand for operating concepts of a
similar kind in the industry. The successes and
potentials of all current and future further
developments are exclusively defined through
usability and design. There is no significant
demand for hover gesture in handheld devices
and mobile devices in the consumer market
or in the industrial market, and, so far, PCAP
with haptic feedback has not taken hold as a
technology in consumer electronics, nor is it
found much - following the chronology - in
industrial applications. However, in critical
industrial areas with high safety control spec-
ifications such as intensive care or the food
sector, the benefits of Force Touch technol-
ogy are evident. The redundancy function-
ality combined with the tested PCAP Touch
technology meets the user basic requirements.
The integration of sensors for the measure-
ment of mechanical force absorption or the
touch-triggering surface remains a challenge.
The latter requires special, non-standardized
touch controllers and high-resolution touch
sensors for touch surface measurement, devel-
opment expertise and technological research.
The market response will ultimately show
which of the PCAP enhancements will take
hold. A combination of several technologies
such as haptic functions and force sensing
remains promising.
n
Figure 2. Schematic layout of a Force Touch panel
