Touch Screen

What Does Touch Screen Mean?

A touch screen is a computer display screen that serves as an input device. When a touch screen is touched by a finger or stylus, it registers the event and sends it to a controller for processing.


A touch screen may contain pictures or words that the user can touch to interact with the device.

Techopedia Explains Touch Screen

A touch screen has two main advantages. First, it allows users to interact directly with what is displayed, rather than indirectly with a pointer controlled by a mouse or touchpad. Secondly, it does not require the use of an intermediate device. Touch screens can be attached to computers or to networks as terminals. They also play a prominent role in the design of digital appliances such as the personal digital assistant (PDAs), satellite navigation devices, mobile phones and video games.

How a touch screen event is registered depends on the touch screen’s inherent technology. The three main touch screen technologies are:

  • Resistive: This screen has a thin metallic layer that is conductive and resistive, so that touching results in a change in the electrical current sent to the controller. Pros: More affordable, not damaged by dust or water, responds to finger or stylus. Cons: Only 75% clarity and susceptible to damage by sharp objects.
  • Surface Acoustic Wave (SAW): Ultrasonic waves pass over this screen. Touching it results in absorption of part of the wave, registering the position of the touch, which is sent to the controller. Pros: Responds to finger or stylus. Cons: May be damaged by dust or water.
  • Capacitive: This screen is coated with an electrically-charged material. Touching it causes a change in capacitance, which allows the location to be determined and sent to the controller. Pros: Not damaged by dust or water and has high clarity. Cons: Must be touched with a finger only – a stylus cannot be used.

There are other, less-common touch screen technologies. These include:

  • Dispersive Signal Technology: Introduced in 2002 by 3M, sensors detect mechanical energy during a touch. Complex algorithms interpret the data to determine the location, and data is sent to controllers. Pros: Durability, not affected by elements, excellent clarity and finger or stylus may be used. Cons: After the initial touch, the system is not able to detect a motionless finger or stylus.
  • Acoustic Pulse Recognition: This system was released in 2006 by Tyco International’s Elo division. It uses transducers located around the screen to transform vibration into electrical energy via algorithms that determine location. Pros: Good durability and clarity, resistant to the elements and well-suited to large displays. Cons: Cannot detect a motionless finger.
  • Infrared: Detects touch via an array of light-emitting diodes (LEDs) and photo-detector pairs at the edge of the screen. Pros: No damage by elements, a finger or stylus may be used, highly durable with high clarity.
  • Optical Imaging: Image sensors (cameras) placed at the edge of the screen pick up infrared black lights on the opposite side of the screen. Pros: Scalable, versatile, affordable and can be used for large displays.

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Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…