What are ResistiveTouch screen and Projected Capacitive Touch Screen
I: 4 Wire Resistive Touch Screen
Introduction of 4 Wire Resistive Touch Screen
4 Wire Resistive Touch Screen is of the most extensive application. It
is capable of working by any kinds of physical touches, such as finger, gloved
hand (any kinds of gloves). It is liquid resistance and contamination proof and
even works in bad environment such as foul, dirt, greasiness. 4 Wire Resistive
touch screen is also noted for its high accuracy and reliability with low cost
advantage. Therefore it becomes the most popular touch screen in applications,
especially in handset device uses.
4 Wire Resistive
Touch Screen Advantages:
.Low
cost
.Finger,
gloved hand and stylus activation
.High
accuracy and sensitivity
.High
durability and reliability
.Contaminant
proof and liquid resistance.
4 Wire Resistive
Touch Screen Working Principle:
The 4 Wire Resistive Touch Screen is a two-layer structure,
1. ITO glass substrate with one side uniform resistive ITO coating.
2. A very thick polyester ITO film which tightly suspended over the top of ITO
glass substrate. This PET film has a hard, durable coating on the outer side,
on inner side with ITO coating.
3. ITO glass and the ITO film are separated by printed small, transparent
insulation spacer dots.
When the screen is touched, it pushes the
ITO film to have an electrical contact with ITO glass (both on the ITO coating
side). It produces a voltage which is the analog representation of the position
touched.
In 4 Wire
Resistive, the ITO glass (glass substrate) is set as Y axis, and ITO film as X
axis. The microprocessor of controller applies +5V voltage to XL (X axis left)
on the ITO film, and the voltage uniformly decreases to XR(X axis right) in
zero voltage. In the same process, the microprocessor applies +5V voltage to YU
(Y axis up) on the ITO glass, and the voltage uniformly decreases to YD (Y axis
down) in zero voltage. When the screen is not touched, the controller detects
the voltage on ITO glass / ITO film as zero voltage.
When the
screen is touched, the voltage on the ITO film proportional to the X axis
(horizontal) position of the touch point appears on the ITO glass. Next, the
voltage on the ITO glass proportional to the Y axis (vertical) position of the
touch point appears on the ITO film. These two voltages appearing on the ITO
film and ITO glass are digitized by the A/D converter and then transmitted to
the host.
The
controller will receive all data to get the touched position according to the
established calculating mode to figure out the exact X and Y coordinates.
4 Wire Resistive Touch Screen Applications:
.Light industrial
.Home appliances
.Portable sport devices
.Access control terminals
.Portable medical devices
II: 5 Wire Resistive Touch Screen
Introduction of
5 Wire Resistive Touch Screen:
5 Wire Resistive Touch Screen is
of the most extensive application. It works by any kinds of physical touches,
such as finger, gloved hand, rubber, etc. It is liquid resistance and
contamination proof and even works in bad environment such as foul, dirt,
greasiness, etc.
5 Wire Resistive Touch Screen Advantages:
.Long
lifetime (almost ten times of 4 Wire Resistive Touch Screen)
.Finger,
gloved hand and stylus activation
.Contaminant
proof and liquid resistance
.High
accuracy and durability
.High
resolution and sensitivity
5 Wire Resistive
Touch Screen Working Principle:
The 5 Wire Resistive Touch Screen is a two layer structure,
1.ITO glass substrate with one side uniform resistive ITO coating.
2. A very thick polyester ITO film is tightly suspended over the top of ITO
glass substrate. This ITO film has a hard, durable coating on the outer side,
on an inner side with ITO coating.
3.The ITO glass and the ITO film is separated by printed small,
transparent insulation spacer dots.
When the screen is touched, it pushes the
ITO film to have an electrical contact with ITO glass (both on the ITO coating
side). It then produces a voltage which is the analog representation of the
position touched.
The 5 wire touch screen controller is
always ready for a touch, and the resistive layer of touch screen is biased at
+5V through 4 drive lines on the glass (ITO coating side) and the ITO film is
grounded through a high resistance. When there is no touch on the screen, the
voltage is zero on the ITO film. The voltage level of the ITO film is analog -
to - digital converter (A/D converter) and monitored by the microprocessor on
the controller.
When the screen is touched, the
microprocessor detects the voltage rise in the ITO film and begins to convert
the coordinates. The microprocessor places the X drive voltage by applying +5V
voltage to pins H, X and grounding pins Y and L. The analog voltage is
proportional to the X position (horizontal) of the touch point and appears on
the ITO film at pin S of the touch screen tail's connector. This voltage is
digitized by the A/D converter and transmitted to the computer.
In same process, the microprocessor places
the Y drive voltage by the same +5V to pins H, Y and ground pins X and L. The
analog voltage is proportional to the Y position (vertical) of touch point and
appears on the ITO film at pin S of the touch screen tail's connector. The
signal is converted and processed same as for the X position.
The controller will receive all data to
calculate the touched position according to pre-established modes for the exact
X and Y coordinates.
5 Wire Resistive Touch Screen Applications:
5 Wire Resistive touch screen is with the most extensive applications.
.Point-of-Sale
uses: convenience store, movie theater, lottery terminal, fast food, etc.
.Industrial
uses: Automated testing, automation equipment, man.machineinterface, etc.
.Medical
uses: medical instrument, research equipment and patient monitoring
system.
.Transportation
uses: Inner vehicle control panel.
III: Projected Capacitive Touch Screen
Introduction of Projected Capacitive Touch Screen
The touch
sensitive layer of pcap sensor consists of a series of micro-fine wires which
are not visible on an active screen. In contrast to the "surface
capacitive touch " system, in which the sensor resides on the surface of
the touch panel , there is the sensor at the "projected capacitive touch
" system in the screen between the laminated glass .
Not only does this technology provides a highly
reliable , low-maintenance system , but it also offers unrivaled protection
against a wide range of physical threats a cost effective solution for the most
demanding ( public ) applications
Projected capacitive ( PCAP ) touch screen
sensors , also known as PCT , offer a range of benefits that are not available
with any other touch sensor technology.
Projected Capacitive Touch Screen Advantages:
• Excellent readability - light transmission of up to 91% through a standard
sensor.
• Ideal for internal and external use - a proven solution for public locations.
• Excellent optical clarity - the sensor can be improved with various coatings
and optical filters.
• Accuracy - less than +/- 1.5% of the set position.
• Response time - <20ms.
• Stability - no drift, therefore no need for calibration.
• Pointing device - works with finger and glove (leather and rubber).
• Immunity to damage - unsurpassed impact, vandal, and scratch resistance.
• External environments - unaffected by dirt, moisture and rain.
• Operating temperature - ranges from -35ºC to + 65ºC. Sub Zero operation can
be realized by making use of an integrated heating panel.
• Resistance to infection - is not affected by harsh detergents.
• Supports both RS232 and USB.
• Controller - further improved in terms of reliability and longevity. (HID
compatible controllers)
• Number of touches: currently 2 (duotouch), 5, 10 and 32 touches for
multiuser applications.
• Supported operating systems - Windows 9x, NT, ME, 2000, XP, XPe, Vista,
Windows 7, 8 and 10, Andoid, Mac and Linux. (For Windows 7, 8 and
10, no driver installation).
Projected Capacitive Touch Screen Specifications:
• The touch sensor consists of laminated
glass in which the sensor situated between the glass. The controller is
connected to the communication port on your computer (USB or RS232).
• Detection method: Dynamic capacity with the aid of horizontal and vertical
wires with a diameter of 10 microns.
• Power current: Typical 5mA at 6 to 12 volts, which is provided by RS232 port, USB or
external.
• Connector: Female D9 serial connector, 3 wire and 3 meters long. Maximum
cable length is 10 meters. Components of the power supply are two diodes,
resistor and a capacitor.
• Operating Temperature: -35 ° C to + 65 ° C
• Humidity: 0 to 90% RH at 40 ° C. Unaffected by condensation.
• Response: 13msec through 4mm thick glass.
• Sustainability: Unsurpassed vandal resistant and shock resistance.
• Accuracy: Less than 1.5% of diagonal error within the display area.
• Sensitivity: adjustable via firmware, max thichness of 6mm glass.
| For Zytouch adjustable by software. A maximum thickness of
20mm from the sensor to the touch surface.
• Detection: Fingers, stylus pen for pcap and gloves.
• Protection from Contamination: Unaffected by harsh detergents, solvents,
grease and dirt.
• Light transmission: 88% through the standard sensor.
• Immunity to Damage: Tempered glass protects the touch sensors.
• Stability: Using fixed wires(Zytouch) wafer pattern ensures that there is no
drift.
• Glass options: Clear, anti-glare, tempered, depending on top glass you
would like to use.
• MTBF (Sensor): Excellent, no known mechanism wear.
• MTBF (Controller): More than 1 million hours - Bellcore TR332.
• Regulatory: Controller will be compatible with the CE and UL when installed
in the system.
• Emissions: passes FCC Class B when installed in the system.
• Seal Severability: Ability to be 12 or NEMA 4 compliant to NEMA.
• Bundled Software: Easy calibration and installation under Windows 98, NT,
2000, XP, 7, 8, 10, and Linux. No calibration on windows needed
• Mouse emulation software, to touch Select, to pause, to let go and drop.
PCAP touch controller Shenzhen Bolinia Technology Co., Ltd. are using is usually industrial EETI touch or consumer ILITEK touch.
2017 06/20