Touchscreens explained: Capacitive and resistive technology compared
Not all touchscreens are created equal. In this article, we review the
different technologies
used in touchscreen phones.
different technologies
used in touchscreen phones.
Touchscreen phones have become more popular over the last few years.
By removing a physical
keypad, touchscreens free up more space to display rich multimedia
content. They’re also a lot
more intuitive to use: a QWERTY keyboard can be used to input texts
and gestures such as “pinch
to zoom” and scrolling make it easy to browse through your photos and
web pages.
By removing a physical
keypad, touchscreens free up more space to display rich multimedia
content. They’re also a lot
more intuitive to use: a QWERTY keyboard can be used to input texts
and gestures such as “pinch
to zoom” and scrolling make it easy to browse through your photos and
web pages.
In this article, we look at the technologies used to create touchscreen
phones and some of the
terminology used in the industry. We also explore the key differences
between different types
of touchscreen phones.
phones and some of the
terminology used in the industry. We also explore the key differences
between different types
of touchscreen phones.
How do touchscreens work?
There are two different types of touchscreens:
- Resistive (Pressure sensitive)
- Capacitive (Sensitive to your body’s electric field)
Traditionally, most touchscreens have been built using resistive technology
although in recent years,
the industry has moved towards capacitive technology for touchscreens.
although in recent years,
the industry has moved towards capacitive technology for touchscreens.
What is a resistive touchscreen?
Resistive touchscreens are pressure-sensitive. They work by detecting the
amount of force which is
applied to the screen. It doesn’t matter how you apply the force: you could
press it with your finger,
use a stylus or prod it with a stick. It really doesn’t matter. Generally you’ll
have to apply a fair bit
of pressure (a fair bit of force in a small area) to a resistive touchscreen for
it to register a response –
most people use the tip of their fingernail or occasionally a stylus (by reducing
the area of contact
you increase the pressure applied).
amount of force which is
applied to the screen. It doesn’t matter how you apply the force: you could
press it with your finger,
use a stylus or prod it with a stick. It really doesn’t matter. Generally you’ll
have to apply a fair bit
of pressure (a fair bit of force in a small area) to a resistive touchscreen for
it to register a response –
most people use the tip of their fingernail or occasionally a stylus (by reducing
the area of contact
you increase the pressure applied).
Resistive touchscreens consist of two surfaces separated by a resistive material.
The surfaces are
flexible so by applying a force to the screen, the two sheets will be pressed
together. This changes
the resistance between the two surfaces. The touchscreen measures this change
in resistance.
The surfaces are
flexible so by applying a force to the screen, the two sheets will be pressed
together. This changes
the resistance between the two surfaces. The touchscreen measures this change
in resistance.
As the oldest and simplest touchscreen technology, resistive touchscreens are
cheap to produce. For
this reason, they tend to be found in older or cheaper phones.
cheap to produce. For
this reason, they tend to be found in older or cheaper phones.
What is a capacitive touchscreen?
Capacitive touchscreens are sensitive to your body’s electric field. Capacitive is
now the dominant
technology for new high-end smartphones such as the Apple iPhone, HTC Desire
and Blackberry
Torch. Because capacitive touchscreens simply “sense” the existence of your
finger electrically rather
than requiring you to push down on the touchscreen they tend to be much more
responsive. For example
, it’s possible to simply glide your finger along the screen (e.g. unlock gesture) –
something which is
difficult with a resistive touchscreen.
now the dominant
technology for new high-end smartphones such as the Apple iPhone, HTC Desire
and Blackberry
Torch. Because capacitive touchscreens simply “sense” the existence of your
finger electrically rather
than requiring you to push down on the touchscreen they tend to be much more
responsive. For example
, it’s possible to simply glide your finger along the screen (e.g. unlock gesture) –
something which is
difficult with a resistive touchscreen.
Disadvantages of capacitive touchscreen technology is that you cannot used it
with gloves on (your body’s
electric field cannot pass through the glove) and it cannot be used with a traditional
mechanical stylus.
Special capacitive touchscreen styluses are available.
with gloves on (your body’s
electric field cannot pass through the glove) and it cannot be used with a traditional
mechanical stylus.
Special capacitive touchscreen styluses are available.
Capacitive touchscreen technology also tends to be more expensive and is hence
seen mainly in
higher-end smartphones. Prices have been coming down however… for example
the Orange San
Francisco is available for £99 on Pay As You Go and includes a capacitive touchscreen.
seen mainly in
higher-end smartphones. Prices have been coming down however… for example
the Orange San
Francisco is available for £99 on Pay As You Go and includes a capacitive touchscreen.
What about multi-touch?
Multi-touch simply refers to a touchscreen implementation which can detect more
than one finger at once.
This can be used for advanced gestures such as “pinch to zoom” (seen on the
iPhone and Android).
Multi-touch screens are generally built on capacitive technology.
than one finger at once.
This can be used for advanced gestures such as “pinch to zoom” (seen on the
iPhone and Android).
Multi-touch screens are generally built on capacitive technology.
Which touchscreen technology is better?
The general consensus in the industry is that a capacitive touchscreen is the way
to go. It’s a more
pleasant experience being able to use your finger rather than a finger nail or stylus
and the touchscreen is
much more responsive. With the costs of capacitive technology falling rapidly, it’s
difficult to find a
reason to choose resistive technology over capacitive technology unless you
regularly use your phone
in cold climates/outdoors where you’ll be wearing gloves.
to go. It’s a more
pleasant experience being able to use your finger rather than a finger nail or stylus
and the touchscreen is
much more responsive. With the costs of capacitive technology falling rapidly, it’s
difficult to find a
reason to choose resistive technology over capacitive technology unless you
regularly use your phone
in cold climates/outdoors where you’ll be wearing gloves.
What type of touchscreen technology do the latest
smartphones have?
smartphones have?
Almost all of the latest high-end smartphones feature capacitive technology
(Apple iPhone, HTC Desire,
HTC Wildfire, Samsung Galaxy S, Blackberry Torch, Nokia N8, etc).
Generally resistive technology
will only be found in older or low-end touchscreen phones.
(Apple iPhone, HTC Desire,
HTC Wildfire, Samsung Galaxy S, Blackberry Torch, Nokia N8, etc).
Generally resistive technology
will only be found in older or low-end touchscreen phones.