Touch Screens:

Interactivity with technology

By Luis Hidalgo

What is a touch screen?

A touch screen is an electronic display on technology that utilizes a screen. This technology allows users to interact with the digital contents displayed on a screen. This technology has been around since the 60s, but didn’t become popular and more common until 2007 when Apple released the first iPhone completely changing the way people use and interact with technology, replacing the analogue keyboard and the mouse with a screen display.

How do touch screens work?

A touch screen works by using a digitizer to turn physical interaction (touching the screen, to type, create pictures and drawings, etc.) into digital signals. Touch screens utilize electricity and touch sensitive detectors. The display of the touch screen uses a nonconductive material such as glass coated with a layer of conductive material called indium tin oxide. This material has a low voltage connected to it giving it a small electric charge, so  when a finger touches the screen the charge goes to it. The touch sensitive detector then finds the point on the screen that lost the electrical charge allowing it to detect which point on the screen has been touched.

Types of touch screen?

Capacitive: the screen panel is coated with material that stores electrical charge and with circuits at each corner the charge is measured  and the information is sent to be processed. Most commonly used in phones, tablets, and some laptops, capacitive touch screen allows for the best clarity with high sensitivity and responsiveness for the best performance

Resistive: resistive touch screens have panels that are coated with a thin metallic layer that is both conductive and resistive. When touched a change in electrical current occurs and this change is registered and processed. Resistive touch screens are commonly used on camera screens, in-flight entertainment, medical equipment, and Global Positioning systems (GPS). 

Infrared: Infrared touch screens use infrared beams which are sent out by light-emitting diodes/LEDs with a receiving end. When the beam is blocked by a finger on the display the interruption gives an input on where the finger is located. Infrared screens are used in ATMs, interactive white board/smart board, factory automation, and  office automation

Keywords

• Display: an image or picture superimposed on a screen
• Interact: to engage in an action, physical or otherwise
• Digitizer: A computer input device that allows users to draw images and graphics
• Digital signal: A signal that represents a sequence of information collected
• Touch Sensitive Detectors: Are also called tactile sensors, is a device that recognizes and records physical touch on a screen or other device
• Nonconductive: unable to conduct electricity
• Conductive: to be able to or have the of conducting electricity to a certain extent
• Voltage: The quantitative expression of the force of a potential charge that allows electrons to flow
• Screen Panel: An electronic screen on which information is displayed
• Circuit: A fixed circular path that electricity flows through
• Capacitive: having the potential or properties of being able to collect and hold an electrical charge
• Resistive: having the potential to withstand the action or effect of pressure
• Infrared: A type of energy that can’t be seen with the human eye, can only be felt as heat