Touch Screens are display as well as input devices. These are electronic
visual devices that are sensitive to pressure thus detect the presence and location of
a touch within the display area. The screens are sensitive to pressure; a user
interacts with the computer by touching pictures or words on the screen. The term
“Touch” generally refers to touch or contact to the display of the device by a finger
Neonode has patented and commercialized the zForce (an abbreviation for
“zero force necessary”) touch technology, which was designed to overcome many
of the limitations of today’s touchscreens. The premise of the company’s approach
entails the projection of an infrared grid across an electronic display. As users tap,
swipe, or write on the screen, zforce detects the location of the touch based on the
Interruption in infrared light projecting across the screen, which translates to
coordinates on the grid. The zforce architecture and input method is believed to be
unique to Neonode.
A zforce Touch Screen can be activated by multiple modes of input,
including bare fingers, gloves, styluses, and (multiple simultaneous to touches).It is
uncommon today to find both pens as well as recognizes multi touch these features
innately built into the same touchscreen. This contact sends a signal to the device
to recognize the touch. Although relatively low cost, resistive touchscreens do not
typically allow multi-touch(swiping, gesturing).
About Neonode Inc. : Neonode Inc. is the leading provider of optical touch
screen solutions for hand-held and small to midsize devices. Neonode is offering
software licenses and engineering design services that enable companies to make
high functionality touch screens at a low cost. zForce ® is the name of Neonode’s
proprietary patented touch screen technology. Neonode Inc. is listed on the OTCBB
under the symbol NEON.OB. Neonode is a trademark and zForce® is a registered
trademark of Neonode Inc.
zForce® : Neonode’s patented touch solution for portable devices, zForce, is
many times more cost effective than any other high performance touch solution in
the market today. zForce® supports high resolution pen writing in combination with
finger navigation including gestures, multi-touch, sweeps and much more. zForce®
doesn’t require an overlay on top of the display window and provide a 100% clear
viewing experience. zForce is the only viable touch screen solution that operates on
the new revolutionary reflective display panels. zForce® is currently being
integrated into a variety of mobile phones, eReaders, automotive applications,
mobile internet and tablet devices.
Touch screens originally emerged from academic and corporate research labs
in the second half of the 1960s. In 1971, the first "touch sensor" was developed by
Doctor Sam Hurst (founder of Elographics) while he was an instructor at the
University of Kentucky. This sensor was called the "Elograph" and was patented by
The University of Kentucky Research Foundation. One of the first places where
they gained some visibility was in the terminal of a computer-assisted learning
terminal that came out in 1972 as part of the PLATO project. They have
subsequently become familiar in kiosk systems, such as in retail and tourist settings,
on point of sale systems, on ATMs and on PDAs where a stylus is sometimes used
to manipulate the GUI and to enter data. The popularity of smart phones, PDAs,
portable game consoles and many types of information appliances is driving the
demand for, and the acceptance of, touchscreens. The HP-150 from 1983 can be
considered as the world's earliest commercial touch screen computer. It doesn't
actually have a touch screen in the strict sense, but a 9" Sony CRT surrounded by
infrared transmitters and receivers which detect the position of any nontransparent
object on the screen.
Until the early 1980s, most consumer touch screens could only sense one
point of contact at a time, and few have had the capability to sense how hard one is
touching. With commercialization of touchscreens the technology used changed to
multipoint technology from dingle point. Historically, the touchscreen sensor and its
accompanying controller-based firmware have been made available by a wide array
of after-market system integrators and not by display, chip or motherboard
manufacturers. With time, however, display manufacturers and chip manufacturers
worldwide have acknowledged the trend toward acceptance of touchscreens as a
highly desirable 4 user interface component and have begun to integrate
touchscreen functionality into the fundamental design of their products.
The Touch Screens come with a variety of definite advantages over
normal/conventional input-output devices. Some of them are :
Easy to use: This provides for a rich user interface experience as this
supports for a very intuitive easy to use environment and is facilitated by just
Saves space: In this world where cost of real estate [i.e., property prices]
are sky rocketing intelligent utilization of space is of great importance. Thus
touch screens facilitate for this by saving space of keyboard and this finds
many application in day today activities.
Speed and Reliability: While laptops do come with a mouse pad and a
USB port to allow you to attach an external mouse to your laptop for easier
navigation, the amount of time spent to do simple navigations with these
devices are extremely slow as compared to simply touching the screen and
pointing directly at the option. Having a touchscreen laptop would make
navigation extremely faster and more reliable. No need to worry about
clicking the wrong option, especially if you are making transactions over the
A basic touchscreen has three main components: a touch sensor, a controller,
and a software driver. The touchscreen is an input-output device, so it needs to be
combined with a display and a PC or other device to make a complete touch input
A touch screen sensor is a clear glass panel with a touch responsive surface.
The touch sensor/panel is placed over a display screen so that the responsive area of
the panel covers the viewable area of the video screen. There are several different
touch sensor technologies on the market today, each using a different method to
detect touch input. The sensor generally has an electrical current or signal going
through it and touching the screen causes a voltage or signal 5 change. This voltage
change is used to determine the location of the touch to the screen.
The controller is a small PC card that connects between the touch sensor and
the PC. It takes information from the touch sensor and translates it into information
that PC can understand. The controller is usually installed inside the monitor for
integrated monitors or it is housed in a plastic case for external touch add-
ons/overlays. The controller determines what type of interface/connection you will
need on the PC. Integrated touch monitors will have an extra cable connection on
the back for the touchscreen. Controllers are available that can connect to a
Serial/COM port (PC) or to a USB port (PC or Macintosh). Specialized controllers
are also available that work with DVD players and other devices.
The driver is a software update for the PC system that allows the touchscreen
and computer to work together. It tells the computer's operating system how to
interpret the touch event information that is sent from the controller. Most touch
screen drivers today are a mouse emulation type driver. This makes touching the
screen the same as clicking your mouse at the same location on the screen. This
allows the touchscreen to work with existing software and allows new applications
to be developed without the need for touchscreen specific programming. Some
equipment such as thin client terminals, DVD players, and specialized computer
systems either do not use software drivers or they have their own built-in touch
TYPES OF TOUCH SCREEN TECHNOLOGIES
A resistive touchscreen panel comprises several layers, the most important of
which are two thin, transparent electrically-resistive layers separated by a thin
space. These layers face each other with a thin gap between. The top screen (the
screen that is touched) has a coating on the underside surface of the screen. Just
beneath it is a similar resistive layer on top of its substrate. One layer has
conductive connections along its sides, the other along top and bottom. A voltage is
applied to one layer, and sensed by the other. When an object, such as a fingertip or
stylus tip, presses down onto the outer surface, the two layers touch to become
connected at that point: The panel then behaves as a pair of voltage dividers, one
axis at a time. By rapidly switching between each layer, the position of a pressure
on the screen can be read.
Resistive touch is used in restaurants, factories and hospitals due to its high
resistance to liquids and contaminants. A major benefit of resistive touch
technology is its low cost. Additionally, as only sufficient pressure is necessary for
the touch to be sensed, they may be used with gloves on, or by using anything rigid
as a finger/stylus substitute. Disadvantages include the need to press down, and a
risk of damage by sharp objects. Resistive touchscreens also suffer from poorer
contrast, due to having additional reflections from the extra layer of material placed
over the screen.
A capacitive touchscreen panel consists of an insulator such as glass, coated
with a transparent conductor such as indium tin oxide (ITO). The human body is
also an electrical conductor, touching the surface of the screen results in a distortion
of the screen’s electrostatic field, measurable as a change in capacitance. Different
technologies may be used to determine the location of the touch. The location is
then sent to the controller for processing.
Unlike a resistive touchscreen, one cannot use a capacitive touchscreen
through most types of electrically insulating material, such as gloves. This
disadvantage especially affects usability in consumer electronics, such as touch
tablet PCs and capacitive smartphones in cold weather. It can be overcome with a
special capacitive stylus, or a special-application glove with an embroidered patch
of conductive thread passing through it and contacting the user's fingertip.
The largest capacitive display manufacturers continue to develop thinner and
more accurate touchscreens, with touchscreens for mobile devices now being
produced with 'in-cell' technology that eliminates a layer, such as Samsung's Super
AMOLED screens, by building the capacitors inside the display itself.
A simple parallel plate capacitor has two conductors separated by a dielectric
layer. Most of the energy in this system is concentrated directly between the plates.
Some of the energy spills over into the area outside the plates, and the electric field
lines associated with this effect are called fringing fields. A parallel plate capacitor
is not a good choice for such a sensor pattern. Placing a finger near fringing electric
fields adds conductive surface area to the capacitive system. The additional charge
storage capacity added by the finger is known as finger capacitance, CF.
III. PROJECTED CAPACITANCE
Projected Capacitive Touch (PCT; also PCAP) technology is a variant of
capacitive touch technology. All PCT touch screens are made up of a matrix of rows
and columns of conductive material, layered on sheets of glass. This can be done
either by etching a single conductive layer to form a grid pattern of electrodes, or by
etching two separate, perpendicular layers of conductive material with parallel lines
or tracks to form a grid. Voltage applied to this grid creates a uniform electrostatic
field, which can be measured. When a conductive object, such as a finger, comes
into contact with a PCT panel, it distorts the local electrostatic field at that point.
This is measurable as a change in capacitance. If a finger bridges the gap between
two of the "tracks", the charge field is further interrupted and detected by the
controller. The capacitance can be changed and measured at every individual point
on the grid (intersection). Therefore, this system is able to accurately track touches.
Due to the top layer of a PCT being glass, it is a more robust solution than less
costly resistive touch technology. Additionally, unlike traditional capacitive touch
technology, it is possible for a PCT system to sense a passive stylus or gloved
fingers. However, moisture on the surface of the panel, high humidity, or collected
dust can interfere with the performance of a PCT system. There are two types of
PCT: mutual capacitance and self-capacitance.
In this technology infrared (IR) light-emitting diodes(LEDs) are placed at the
opposite edges to analyze the system and detect the touch event. The LED and
photo sensor pairs create a grid of light beams across the display. An object (such as
a finger or pen) that touches the screen interrupts the light beams, causing a
measured decrease in light at the corresponding photo sensors. The measured photo
sensor outputs can be used to locate a touch-point coordinate.
Widespread adoption of infrared touchscreens has been hampered by two
factors: the relatively high cost of the technology compared to competing touch
technologies and the issue of performance in bright ambient light. This latter
problem is a result of background light increasing the noise floor at the optical
sensor, sometimes to such a degree that the touchscreen’s LED light cannot be
detected at all, causing a temporary failure of the touch screen.
However, certain features of infrared touch remain desirable and represent
attributes of the ideal touchscreen, including the option to eliminate the glass or
plastic overlay that most other touch technologies require in front of the display. In
many cases, this overlay is coated with an electrically conducting transparent
material such as indium-tin oxide (ITO), which reduces the optical quality of the
display. This advantage of optical touchscreens is extremely important for many
device and display vendors since devices are often sold on the perceived quality of
the user display experience.
Another feature of infrared touch which has been long desired is the digital
nature of the sensor output when compared to many other touch systems that rely on
analog-signal processing to determine a touch position.
V. ZFORCE TOUCHSCREEN TECHNOLOGY
Neonode overcomes limitations of both resistive and capacitive screens with
its zForce® technology creating a next-generation touch surface that the Company
believes can be more economical as well as higher performing than either of the
main technologies in use today. Currently, projected-capacitance touch screens
represent the mainstream technology for multi-touch interfaces. However, zForce®
also enables the convenient multi-touch features of capacitive screens but at the cost
structure of more affordable resistive technologies. Further, as overviewed on, in
February 2012, the Company introduced a new Multi Sense component to the
zForce® technology that is intended to improve upon standard multi-touch
In contrast to capacitive and resistive screens, which have microscopic
circuits embedded on a glass substrate, Neonode’s controller projects a grid of
infrared light beams across the display layer. Importantly, the Company’s
technology is display agnostic and can be added to variety of display surfaces,
including liquid-crystal display (LCD), eink, organic Light emitting diodes
(OLED),and electronic paper displays (EPD). Touch is detected as a finger or object
interrupts (by obstructing or reflecting) the light beams projected across the screen
surface, which identifies the X and Y coordinates of the touch. As illustrated in
Figure 11, there is no glass substrate or glass overlay required.
A plastic light guide is located under the bezel on top of the display. It serves
to reflect and focus light are shown attached to a around the zForce® display. LEDs
and photo diodes printed circuit board (PCB) display. The zForce Technology
pulses an infrared light across the screen at a rate of up to 120 times a second so the
grid is continuously refreshed. As the user’s fingers move across the screen, the
grid’s coordinates where the screen is touched are converted into mathematical
algorithms in a process that is unique to Neonode.
The newer and higher-cost capacitive technology, such as that used on Apple
Inc.’s (AAPL NASDAQ) iPhone, is activated by conductive material rather than
applied pressure. Electrodes in the display contact with an electrical conductor, such
as a finger. Capacitive devices perform multi touch but cannot be activated by
standard pointers or gloves as these are nonconductive.. As a result, many users find
that their touchscreen can recognize taps from their fingers but not finger nails.
zTouch™ is a Force Based touch screen technology. One of the key
advantages of force based touch screen technologies is that as the applied touch
force is used for determining the touch coordinates, the touch system will, and must,
also accurately know the magnitude of the user's touch at any given moment of
time. The touch system output is therefore based on 3-variables; x- and y-
coordinates and the "z-coordinate" (force level).
Many companies and organizations have explored the concept of force-based
touch screen technologies over the last 30+ years, but few have been able to bring
the theoretical concepts or laboratory prototypes into working commercial products.
Where others have failed, F-Origin has succeeded.
F-Origin's earliest implementation was a 4" touch panel for a GSM
Smartphone. This phone was in many ways ahead of its time, featuring motion and
touch control and a Java based OS, but was unfortunately only produced in a few
F-Origin has since further developed the zTouch™ touch screen product to
allow for a broad range of product applications, such as POS and POI monitors,
oversized touch monitors, indoor & outdoor kiosks, refrigerator and oven control
panels, bezel and bezel-less designs and much more.
F-Origin's zTouch touch screen technology is built on three competence
areas; mechanical design, sensor technology, and software / algorithms. To ensure
high accuracy, the force sensor must be extremely precise, linear and sensitive. F-
Origin has jointly developed a piezo-resistive force sensor that meets these
While the FFS force sensor capture the data and the mechanical design
ensures an optimal transfer of the touch force from the touch media (touch screen,
touch panel) to the force sensors, it is the zTouch™ software and underlying
mathematical algorithms that ensures performance and accurate coordinate
calculation in the system. The firmware of the default zTouch™ implementation
runs on STM32F101 and STM32F103 family of ST Micro MCUs, however, other
MCUs can be supported.
The main tasks of the zTouch™ firmware are to record & filter the sensor
data, optimize, compensate & calculate the touch coordinates, and to communicate
the touch coordinates.
The zTouch™ architecture is highly flexible and supports touch systems using at
least one (1), and up to eight (8) force sensors. The functional modules of the
firmware includes data filtering and data correction, initial coordinate calculation,
zero moment calculation and auto calibration, motion compensation, touch
threshold determination and data export. Additional support functions, such as the
initialization function allows for certain values and thresholds to be set or
manipulated by user, or even the applications. For example the required force levels
for a touch or a click. Specific end-user calibration module is currently not
supported as a standard configuration, although it can be if requested.
FEATURES OF zFORCE TOUCHSCREEN
Support for any type of touch: User input is recorded independent of
what the user is touching the screen with, e.g., finger with or without glove,
pen, stylus, credit card etc.
Durability: Touch surface/lens is as durable as the system/application
requires. No membrane to wear so routine cleaning procedures and materials
can be used without concern.
Environmental robustness: Moisture/dust resistance as well as the
ability to filter out and ignore weather and contaminants is another benefit of
the design and positive impact to no membrane layer or bezel-based optics
and electronics. Bezel or Bezel-less designs are available.
Optical Performance: Optical performance is enhanced compared to
typical surface-based touch systems because there is no surface membrane to
restrict light transmission. Better clarity and light throughput enhances
viewing experience as well as potentially reducing backlighting thereby
saving system energy usage as well.
Configurable force sensitivity levels: With most of the system’s
intelligence resident in the software, it is simple to adjust force levels
(sensitivity) for different users or applications. This is useful in setting the
minimum pressure necessary to register a particular touch, gesture, or key
press. For example, a light touch may highlight or select a key, while a
harder press could be required to record the key press.
Lens or touch surface design freedom: As long as the lens/touch
surface is rigid, any material may be selected. The shape of the surface could
also be non-rectangular and it may even have 3-dimensional features or
topography such as raised or lowered areas for key orientation effects or
Braille character support.
Gesture Support: The zTouch™ touch screen will register single points,
such as key presses, as well as line drawings and gestures, making this
solution optimal for gesture inputs, drawing, and handwriting recognition
Affordable: The zTouch™ technology is also very cost
effective/competitive, especially for larger volumes, as the cost for unique
components and sensors is comparatively low.
WORKING PRINCIPLE OF ZFORCE
Infrared touch screen is a touch frame which is usually installed in front of
the display screen. The frame is integrated with printed circuit board which contains
a line of IR-LEDs and photo transistors hidden behind the bezel of the touch frame.
Each of IR-LEDs and photo transistors is set on the opposite sides to create a grid of
invisible infrared light. The bezel shields the parts from the operation environment
while allowing the IR beams to pass through.
The infrared Touch Screen controller sequentially pulses less to create a grid
of IR light beams. When a user touches the screen ,enters the grid by a stylus which
can interrupt the IR light beams, the photo transistors from x and Y axes detect the
IR light beams which have been interrupted and transmit exact signals that identify
the X and Y axes coordinates to the host.
An array of infrared LEDs are used to track where fingers on the screen are
the drawback of this kind of technology is that a raised bezel is places around the
screen. This raised bezel houses an array of infrared LEDs and sensors. The new
technology has already been licensed to companies to use this technology. The
swips company has noted that power consumption is as low as 1mw at 100hz.
battery life of tablets devices will benefit from such a new type of touch screen. ims
response times are quite possible with this new technology and there is little to no
Long service life
Long battery life
Can be scaled to any size without losing resolution
scratch, breakage, and liquid resistance
Touch can be activated by anything including finger, gloved hand, or stylus.
Avoid accidental touch
The possibilities are numerous and can be explored further in this technology that is
conceived and promoted by the company Neonode. Implementation of this technology into
practical use would be worth for economic making touchscreen scratch and liquid resistance and
we will proceed towards a better, faster technology. The concept of zForce technology is
currently attracting a great deal of interest, not least because it may offer a genuine and very
efficient alternative to other traditional outdated touchscreens.