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ITE Trans. on MTA Vol. 6, No. 4, pp. 280-285 (2018)
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1. Introduction
The UI (User Interface) is evolving from GUI
(Graphical User Interface), using a keyboard and mouse,
to NUI (Natural User Interface), typified by touch screen
multi-touch and gesture operations. Table 1 shows the
history of user interface evolution [1]. A CLI (Command
Line Interface) is a user interface that uses many
commands, and requires the user to memorize the names
of commands, their parameters, and their syntax. A GUI
is a graphical (visual) user interface using computer
graphics and a pointing device. It is the mainstream
interface for PCs and similar applications.
A NUI is a user interface based on multi-touch
gestures. In recent years, NUI has become the
mainstream for user interfaces in smartphones and
mobile devices.
As the touch screen replaces the keyboard and the
mouse as the interaction device, the user can directly
operate information by using functions such as zooming,
pinching, and flicking. Because interaction mediation as
a pointing device has been eliminated by the touch
screen, the user can operate information in a direct and
natural way.
An OUI (Organic User Interface) is a user interface
that uses nonplanar objects and performs both input and
output operations on said objects. It is expected that this
style of operation will develop as time progresses [2] [3].
Currently, the user interface is at the stage of NUI, and
it is speculated that it will evolve into OUI in the future.
In recent years, seamless multi-device experiences and
user identification on touchscreens [4][5] have attracted
attention in addition to conventional touch functions.
The Microsoft Surface (table type touch display) is a
typical example of a multi-device experience. This device
successfully achieved an advanced multi-device
experience that recognizes objects on the table (e.g., wine
bottles, wine glasses, and smartphones) and the device
can directly interact with digital information on the
screen. However, because this device uses an optical
touch panel, it requires a special pattern arrangement at
the bottom of the object.
Sato et al. (2012) proposes interactive user
differentiation using human electrical properties. This
method uses a novel sensing approach based on Swept
Frequency Capacitive Sensing, which measures the
impedance of a user upon the environment (i.e., ground)
Abstract We describe a novel user interface that utilizes an integrated transparent NFC (Near Field
Communication) antenna on a touch display. Our transparent NFC antenna enables user identification on
touchscreens and seamless multi-device experiences, in addition to the conventional touch function. This
proposed technology allows the user to interact directly and intuitively with digital information through the
display. Moreover, the transparent NFC antenna is compact, featuring advanced design.
Keywords: Transparent NFC Antenna, Natural User Interface, User identification, Multi-device experiences.
Received April 10, 2018; Revised September 12, 2018; Accepted September18, 2018†Sharp Corporation(Nara, Japan)
Integrated Transparent NFC Antennas on Touch Displays
Yasuhiro Sugita† (member), Jean Mugiraneza†, Shinji Yamagishi†
Table 1 History of user interface evolution.
Copyright © 2018 by ITE Transactions on Media Technology and Applications (MTA)
across a range of AC frequencies. Tam Vu et al. (2012)
aim to perform touch ID authentication using a ring
device.
In order to further evolve NUI, the addition of
functions such as seamless multi-device experiences and
ID authentication is required.
Meanwhile, in recent years, communication interfaces
such as NFC have been installed in many products
(mainly smartphones), and electronic payment by
smartphone is dramatically spreading. In addition,
electronic money NFC cards for transportation systems
and shopping systems are rapidly spreading.
Figure 1 shows conventional NFC technology. In
conventional technology, because the display and the
card reader are separated, operation can be very difficult
for users to understand. Furthermore, due to the
evolution of the design, there is the problem of almost no
space being available for antenna placement.
In order to further evolve the UI, the integration of
touch display and NFC becomes very important. In this
paper, we present an integrated transparent NFC
antenna on a touch display. Our prototype realizes
intuitive communication and identification.
2. Transparent NFC Antenna
2.1 Structure
Figure 2 shows a photograph and an overview figure
of a transparent antenna. The antenna is made
transparent, and it is placed on the display module. The
user interface can be made simpler and easier to operate
by matching the information on the screen with the
antenna position. As a result, we can achieve
increasingly natural feedback and intuitive interaction.
Additionally, by eliminating external devices, our
technology enables advanced design even with an ultra-
narrow bezel.
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Paper » Integrated Transparent NFC Antennas on Touch Displays
Fig.3 Details of the cross section structure of an integrated
transparent NFC antenna on a touch display.
(a)
Fig.1 Conventional NFC devices.
(b)
Fig.2 (a) a photograph and (b) an overview figure of a transparent
antenna.
Figure 3 shows the details of the cross section
structure. In the case of a capacitive touch panel, the
transparent antenna is placed between the touch panel
and the display module. In the detailed structure, the X
sensor electrode and the Y sensor electrode of the touch
panel are arranged under the cover glass, and the
transparent antenna electrode is arranged below it. The
touch sensor electrode is made of ITO or a metal mesh
on a PET substrate. The antenna electrode is made of
metal mesh on a PET substrate. The process uses same
lithography and etching technology as in touch panels.
In this prototype, the touch panel and the transparent
antenna are arranged on the display module above the
air gap.
Figure 4 shows the plane view of a transparent
antenna. The antenna size is about 50 mm x 80 mm, the
same as the size of NFC cards used in e-money
transaction. The integrated transparent NFC antenna
on the touch display enables the user to interact
directly, seamlessly, and intuitively with digital
information via the display.
2.2 Multiple-Antenna System
Because the antenna is transparent, it can freely be
placed within the screen, and even multiple antennas
can be arranged.
Figure 5 shows a multiple-antenna system. This
system consists of a touch panel, touch panel controller,
transparent antenna, antenna controller,
microprocessor, and display module. The size of the
antenna controller board is 70 mm x 90 mm. Each
antenna is connected to the antenna controller via an
enabling selector switch. The distance between adjacent
antennas is about 90 mm.
NFC communication for reading and writing is
performed sequentially. By arranging multiple
antennas, the system can identify the position where the
NFC card, smartphone, or object with a built-in NFC tag
is held. In addition, this system can detect the position
of an object using the touch panel, and can drive an
antenna in conjunction with the position information.
3. Results and Discussions
3.1 Communication Performance
Figure 6 shows the cross-sectional structure when
evaluating communication performance. The NFC card
was placed on the touch display, and communication
was confirmed by changing the distance between the
display and the card. Measurement was carried out
under the conditions of success rate and maximum
communication distance.
The success rate requirement is at least 95%
(communication must be successful at least 95 times
when the polling command is executed 100 times.)
The maximum communication distance is the distance
at which the specified success rate is first obtained when
the NFC card is gradually moved closer to the device.
ITE Trans. on MTA Vol. 6, No. 4 (2018)
282
Fig.6 Measurement for maximum communication distance.
Fig.5 Multiple-antenna system.
Fig.4 Plane view of a transparent antenna.
Figure 7 shows the evaluation results of
communication performance. Maximum communication
distances of 75 mm for ISO14443A (Type-A), 25 mm for
ISO14443B (Type-B), and 55 mm for ISO18092 (Felica)
were achieved. For ISO18092 (Felica), the maximum
communication distance of a conventional reader / writer
should be not less than 25 mm. In our transparent
antenna technology, the same performance as a
conventional external reader / writer was obtained.
Figure 8 shows the antenna position of a 20-inch
prototype multiple-antenna system. This prototype has
12 antennas. The distance between two adjacent
antennas was designed to about 90 mm to prevent cross-
talk and erroneous communication. The communication
performance of the multi-antenna system is
experimentally verified.
Figure 9 shows the evaluation results of
communication performance of a multiple-antenna
system. Maximum communication distances of 31 mm
for ISO18092 (Felica) were achieved. The error bars
show 3σ. In this prototype, all antennas share the same
matching circuit between the antenna and the
controller, with differences occurring in communication
performance depending on the different wiring lengths
and structures around the wiring. By tuning and
optimizing the circuit parameters for each antenna
wiring, variation in communication performance due to
antenna position can be minimized. By arranging
multiple antennas, the system can identify the position
where the NFC card, smartphone, or object with a built-
in NFC tag is held.
3.2 Prototype
The transparent NFC antenna-touch display has been
fabricated, and its performance experimentally verified.
Specifications of the prototype are shown in Table 2. The
15-inch prototype uses a single antenna, and the 20-inch
and 42-inch prototypes use multiple antennas, 11 and
12. The 15-inch and 20-inch prototypes can be operated
by a single user for shopping, use with vending
machines, and various forms of entertainment. The 42-
inch prototype allows multiple users to access
information at the same time for signage display
applications. These prototypes were fabricated to verify
and demonstrate the usability and the user experience
in each application.
Figure 10 shows a 15.6-inch prototype that shoppers
can use to pay for purchases by placing an NFC card on
the display. Additionally, shoppers who have registered
credit card information on smartphones equipped with
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Paper » Integrated Transparent NFC Antennas on Touch Displays
Fig.9 Results for communication performance of multiple
antennas of the 20-inch prototype.
Table 2 Specifications of the fabricated transparent NFC
antenna-touch displays.
Fig.7 Results for communication performance of a single antenna
of the 15.6-inch prototype.
Fig.8 Antenna positions for multiple antennas system of the 20-
inch prototype.
NFC can complete payment while shopping simply by
holding the smartphone on the NFC reader or lightly
touching the NFC reader. This prototype successfully
carries out user identification and authentication
through touching the display surface.
Figure 11 shows a 20-inch prototype of a vending
machine. In this case, the prototype has 6 antennas.
Shoppers can complete payment while shopping by
simply holding the smartphone or NFC card on the NFC
reader or lightly touching the NFC reader. Users can
purchase items with one action by simply holding the
NFC card or smartphone over the picture of each item.
This prototype carries out user identification and
authentication through touching the displayed products
on the display surface.
Figure 12 shows a 20-inch prototype. In this case, the
location of the hotel is shown on the map, and the hotel
information is displayed in a balloon. The user operates
the touch panel to move the map and display the target
hotel. Next, by placing a smartphone over the balloon of
the hotel of interest, the user can transfer the hotel
information from the display to the smartphone. In the
presence of multiple displays and smartphones, our
prototype can shift information from the display to
smartphone in a seamless multi-device experience. In
addition, our multiple-antenna system allows multiple
users to access information at the same time.
Information can be seamlessly and intuitively moved
from a display to a smartphone.
Figure 13 shows a 20-inch prototype display that
enables the detection of NFC playing cards. In this case,
the NFC tag is built into the playing card, allowing the
display to identify each card. NFC tags can also embed
information in various objects other than cards or
smartphones. This technology can be applied to various
forms of entertainment and other applications.
In essence, the object itself is a trigger for interaction
with information. Interactive objects interact with
information on touched objects.
In other words, users can directly interact with digital
ITE Trans. on MTA Vol. 6, No. 4 (2018)
284
Fig.13 20" Prototype for various forms of entertainment using
interactive objects.
Fig.10 15.6" Prototype for payment while shopping.
Fig.11 20" Prototype for a vending machine.
Fig.12 20" Prototype for a seamless multi-device experience.
Fig.14 42" prototype for multiple users in shopping malls.
information through various objects, as in the case of
OUI.
Figure 14 shows a 42-inch prototype display. In this
case, our multiple-antenna system allows multiple users
to access information at the same time. Even for signage
display applications that could be used in shopping
malls, multiple users can intuitively operate information
at the same time.
4. Conclusion
Our transparent NFC antenna on a touch display
enables user identification on touchscreens and seamless
multi-device experiences, in addition to conventional
touch functions. This proposed technology enables the
direct interaction of a user with digital information
through the display. Moreover, the transparent NFC
antenna has a compact and advanced design.
As we work to further enable the evolution of NUI, we
are confident that our technology will become a standard
user interface for the future.
In this paper, we successfully created an out-cell type
prototype in which a transparent antenna is placed
apart from the display. From here, we will continue our
research and development of built-in displays (on-cell
type, in-cell type).
5. Acknowledgments
The authors thank H. Kawamori, H. Fukushima, H.
Furukawa, M. Ueno, M. Moriya, and N. Shiobara for
their encouragement and invaluable technical advice.
References
1) Daniel Wigdor, Dennis Wixon "Brave NUI World: DesigningNatural User Interfaces for Touch and Gesture", Elsevier (2011)
2) Vertegaal, R. and Poupyrev, I. "Organic user interfaces" Commun.ACM, vol. 51, pp. 26-30 (2008)
3) Parkes, A. and Poupyrev, I. "Designing Kinetics Interactions forOrganic User Interfaces" Commun. ACM, vol. 51, pp. 58-65 (2008)
4) Harrison, C., Sato, M., and Poupyrev, I. "Capacitive fingerprinting,"Proceedings of the 25th Annual ACM Symposium on User InterfaceSoftware and Technology (ACM UIST '12), pp. 537-543 (2012)
5) Tam Vu, Akash Baid, "Distinguishing Users with Capacitive TouchCommunication" MobiCom'12, Istanbul, Turkey (August 22-26,2012)
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Paper » Integrated Transparent NFC Antennas on Touch Displays
Shinji Yamagishi received a B.S. degree inapplied chemistry engineering from YamanashiUniversity in 1992. He joined Sharp Corp., Japan in1992, where he has been engaged in research on liquidcrystal materials and module technology for LCDs. Heis now a member of the Development Group, DisplayDevice Company, Sharp Corp., Nara, Japan, where heis developing touch-panel technologies and UserInterface technologies for display devices.
Jean Mugiraneza received his B.Sc. inPhysics from Anhui Normal University, Anhui, China,in 2005. He received his M. Sc. Applied Nuclear andParticle Physics from Beihang University, Beijing,China in 2008. He received his Ph.D. in Electrical Eng.from University of the Ryukyus, Okinawa, Japan, in2011. He joined Sharp Corp., Japan in 2012, where hehas been engaged in research on touch-paneltechnology for LCDs. He is now a member of theDevelopment Group, Display Device Company, SharpCorp., Nara, Japan, where he is developing touch-paneltechnologies and User Interface technologies fordisplay devices.
Yasuhiro Sugita received his B.Eng. andM.Eng. degrees in electronics engineering from HoseiUniversity, Tokyo, Japan in 1995 and 1997respectively. He joined Sharp Corp., Japan in 1997,where he has been engaged in research on devices andcircuits for high-density flash memory, RRAM, andembedded non-volatile memory, and began researchingintegrated sensors for system displays in 2008. He isnow a member of the Development Group, DisplayDevice Company, Sharp Corp., Nara, Japan, where heis developing touch-panel technologies and UserInterface technologies for display devices.
