Touch Screen
GDS can integrate the most suitable touch screen technology, finding the right solution based on the end-use application.
Resistive Touch Screen
The touch portion is composed of two transparent conductive layers separated by a thin space. When an object touches the panel, the conductive layers make contact, passing the coordinates to the operating system. GDS recommends that clients consider using glass based rather than plastic PET resistive touch screens to increase the luminance and contrast of images. Optical bonding can also be considered as an option with resistive touch screen to increase optical performance and minimize parallax effects.
Surface Capacitive Touch Screen
The sensor is laminated with glass and will operate even when scratched or damaged. Typically, this sensor has a very hard surface which is extremely durable. It can be touched by fingers or by any conductive device being held by a bare hand.
Projected Capacitive Touch Screen
A grid of transparent conductors (fine wires) projects a field that is able to sense a bare or gloved finger that enters into the field. This means that very light touch (or even hovering above the screen) can trigger the touch event or register more than one touch event at a time (i.e. multitouch). The optical performance of this solution is very good.
Infrared Touch ScreenAn array of vertical and horizontal sensors is used to detect an interruption of the IR rays above the surface of the screen. This solution is very durable but requires a very flat surface and is subject to frequent maintenance.
Surface Acoustic Wave Touch Screen
Ultrasonic waves pass over the touch sensor, so that when the screen is touched, a portion of the acoustic energy is absorbed. The position of the touch is then sent to the controller for processing.
Bending Wave Touch Screen
This relatively new technology effectively 'listens' for a touch event on the display. Piezo transducers are positioned in the corners of the screen, listening for the touch events. Bending wave touch sensors have excellent optical performance, are scratch resistant and will function even when the front surface is dirty or scratched.
Optical Imaging Touch Screen
Similar to Bending Wave, these touch screens feature two infra-red light source optical sensors positioned at the corners of the screen that track the movement of objects near the surface.
Dispersive Signal Touch
DST works on the premise of measuring the mechanical energy (vibrations) within a glass substrate that is created when someone touches the surface of the glass. Sensors, generally placed on the back side of the glass, convert the vibrational energy into electrical signals. DST has exceptional optical characteristics, is resistant to contaminants and can have a very durable glass surface.
