What Are The Different Types Of Touchscreen

We're still emailed quite often and asked to explain the different types of touchscreen displays. So, with that in mind, we’ve decided to provide a simple guide.

A touch screen has the ability to detect a touch within the given display area. It is made up of 3 basic elements, a sensor, a controller and a software driver.

All the variants of touch screen technology carry their own distinctive characteristics, with individual benefits and limitations.

Capacitive Touchscreen

Commonly utilised for industrial purposes, capacitive touch screens consist of a glass overlay, coated with a conductive material such as Indium Tin Oxide. Contact with a capacitive screen creates an electrostatic charge that sends information to the touch control in order to perform its function. This type of touch screen has very good clarity and durability, except they can only respond to the touch of a finger or special gloves unless it is capacitive charged.

Resistive Touch Screen

Wire Resistive Touch is the most widely touch technology in use today. A resistive touch screen monitor is composed of a glass panel and a film screen, each covered with a thin metallic layer, separated by a narrow gap. When a user touches the screen, the two metallic layers make contact, resulting in electrical flow. The point of contact is detected by this change in voltage.

Advantages:

● Can activate with virtually any object (finger, stylus, gloved hand, pen, etc.)

● Has tactile feel

● Lowest cost touch technology

● Low power consumption

● Resistant to surface contaminants and liquids (dust, oil, grease, moisture)

Disadvantages:

● Lower image clarity compared to other touch technologies

● Outer polyester film is vulnerable to damage from scratching, poking and sharp object

SAW (Surface Acoustic Wave) Touch

SAW (Surface Acoustic Wave) touch screen monitors utilize a series of piezoelectric transducers and receivers. These are positioned along the sides of the monitor’s glass plate to create an invisible grid of ultrasonic waves on the surface. When the panel is touched, a portion of the wave is absorbed. This allows the receiving transducer to locate the touch point and send this data to the computer. SAW monitors can be activated by a finger, gloved hand, or soft-tip stylus. SAW monitors offer easy use and high visibility.

Advantages:

● Excellent image clarity

● Even better scratch resistance than surface or projected capacitive

● High “touch-life”

Disadvantages:

● Will not activate with hard items (pen, credit card, or fingernail)

● Water droplets remaining on the surface of the screen can cause false triggering

● Solid contaminants on the screen can create non-touch areas until they are removed

Optical Imaging Touchscreen

Using optical sensors to recognise the touch, this touch screen technology is popular for its versatility and scalability. Optical imaging relies on infrared lights. Two infrared imaging sensors are positioned at the top, which double up as emitters and retro reflective tapes at the three sides. The emitted lights are reflected back to the imaging sensors, which become blocked at the point of touch and create a shadow to locate the touch.

Acoustic Pulse Recognition Touchscreen

An APR touch screen is made up a glass overlay and four transducers attached to the back exterior. When the screen is touched, the friction creates acoustic waves. The transducers detect the acoustic wave, which is then converted into a signal. APR touch screens are water resistant, durable and scalable.

IR (Infrared) Touch Screen

IR (Infrared) type touch screen monitors do not overlay the display with an additional screen or screen sandwich. Instead, infrared monitors use IR emitters and receivers to create an invisible grid of light beams across the screen. This ensures the best possible image quality. When an object interrupts the invisible infrared light beam, the sensors are able to locate the touch point. The X and Y coordinates are then sent to the controller.

Advantages:

● Highest image clarity and light transmission of all touch technologies

● Unlimited “touch-life”

● Impervious to surface scratches

● Multi-touch (two or more touch points)

● Palm Rejection Capability

Disadvantages:

● Accidental activation may occur because the infrared beams are actually above the glass surface

● Dust, oil, or grease buildup on screen or frame could impede light beam causing malfunction

● Buildup of snow and pooling of water (such as rain) can cause false triggering

● May be sensitive to direct high ambient light interference

● Higher cost

For more information about this technology, please get in touch with us.