Touch Screen Technologies
Touch Screen Technologies
Resistive Touch Screen Technology

Resistive touch screens have a flexible top layer and a rigid bottom layer separated by insulating dots, with the inside surface of each layer coated with a transparent conductive coating.

Voltage applied to the layers produces a gradient across each layer. Pressing the flexible top sheet creates electrical contact between the resistive layers, essentially closing a switch in the circuit.



Capacitive Touch Screen Technology

Capacitive touch screens are curved or flat glass substrates coated with a transparent metal oxide. A voltage is applied to the corners of the overlay creating a minute uniform electric field. A bare finger draws current from each corner of the electric field, creating a voltage drop that is measured to determine touch location.



Dispersive (DST) Touch Screen Technology

The DST Touch System determines the touch position by pinpointing the source of "bending waves" created by finger or stylus contact within the glass substrate. This process of interpreting bending waves within the glass substrate helps eliminate traditional performance issues related to on-screen contaminants and surface damage, and provides fast, accurate touch attributes.



Acoustic Wave Touch Screen Technology (SAW)

Acoustic wave touch screens use transducers mounted at the edge of a glass overlay to emit ultrasonic sound waves along two sides. These waves are reflected across the surface of the glass and received by sensors. A finger or other soft tipped stylus absorbs some of the acoustic energy and the controller measures the amplitude change of the wave to determine touch location.



Infrared Touch Screen Technology

Infrared touch screens are based on light-beam interruption technology. Instead of an overlay on the surface, a frame surrounds the display. The frame has light sources, or light emitting diodes (LEDs) on one side and light detectors on the opposite side, creating an optical grid across the screen.

When an object touches the screen, the invisible light beam is interrupted, causing a drop in the signal received by the photo sensors.



Optical Touch Screen Technology

Optical touch screen technology uses two line scanning cameras located at the corners of the screen. The cameras track the movement of any object close to the surface by detecting the interruption of an infra-red light source. The light is emitted in a plane across the surface of the screen and can be either active (infra-red LED) or passive (special reflective surfaces).



However, there are now several different types of multi-touch, depending on the touch technology employed. Below is an explanation of the different types of touch available which also acts as a guide for the terms we use for describing the touch screens we supply.
Single Touch

Single Touch occurs when a finger or stylus creates a touch event on the surface of a touch sensor or within a touch field so it is detected by the touch controller and the application can determine the X,Y coordinates of the touch event.

These technologies have been integrated into millions of devices and typically do not have the ability to detect or resolve more than a single touch point at a time as part of their standard configuration.

Single Touch with Pen Input

Inactive pens enable the same input characteristics as a finger, but with greater pointing accuracy, while sophisticated, active pens can provide more control and uses for the touch system with drawing and palm rejection capabilities, and mouse event capabilities.

Single Touch with Gesture

Since single touch systems can´t resolve the exact location of the second touch event, they rely on algorithms to interpret or anticipate the intended gesture event input. Common industry terms for this functionality are two-finger gestures, dual touch, dual control, and gesture touch.

Touch Gestures.

Two Touch (2-point)

The best demonstration of Two Touch capability is to draw two parallel lines on the screen at the same time. Two Touch systems can also support gesturing.


Multi-touch is considered by many to become a widely-used interface mainly because of the speed, efficiency and intuitiveness of the technology.

To take full advantage of the multi-touch capabilities of this device, you can download multi-touch development applications from the following software companies:
Touchtech Lima
Touchtech Lima is a premium multi-touch software solution. It is designed for multi-touch table and wall displays to create interactive presentations using your existing files (pictures, videos, and documents etc).
NUITEQ´s multi-touch software product Snowflake Suite is a premium multi-touch software solution. It is designed for multi-touch table and wall displays to create interactive presentations using your existing files (pictures, videos, and documents etc).
MultiTouch pack from Aduma is all about engaging touch presentations. It is used across a variety of markets whenever there is a need to captivate and engage an audience.
Omnitapps Multi Touch Suite
Omnitapps Multi Touch Suite is the fully customizable (multi) touch application suite. It offers a collection of applications that offers you a unique way to present your products or services.