Touch screen is an input device which allows the user to operate a computer by employing either their finger or stylus. They are a very useful alternative to a keyboard or mouse for navigating a GUI (Graphical User Interface). Touch screens are frequently used on various devices, including computer and mobile phones, laptops, tablets, and data kiosks. To understand how a touch screen works, it is necessary to first understand what a touch screen display is made of.
Touch screen display units are made up of a transparent display substrate, usually in the form of an LED Light Emitting Diode, usually in liquid crystal. On the backside of the display is a miniature resistive or Capacitive touch screen sensor, typically embedded within a rubberized aluminum enclosure. The sensor is embedded in a housing to shield it from damage. This is the front side of a touch screen display. When a finger of a user presses on the screen, a signal is generated by the sensor and it interacts with the display via the touch screen display sensor.
The screen is usually touch sensitive and can detect the movement of a finger or stylus. In a laptop, a touch sensor is placed on the external monitor to detect the motion of the finger on the screen. The display, powered by an electrical source, shows the finger movement. The display can be configured to show either text or images depending on the use.
The advantage of having a touch screen rather than a traditional computer mouse is that the user can manipulate the interface of the input device much more easily. With the traditional computer mouse, the user has to move the mouse to get to the desired location. To reach a particular item, the user has to turn the mouse wheel in a certain direction. It could take a lot of effort and movement to get to the particular item.
Touch screen technology has also enabled manufacturers to introduce handwriting recognition technology. A number of phones have this handwriting recognition facility built-in. This allows the user to write on the touch screen using the stylus or pen. The writing is then displayed in a recognizer window on the phone. The user can then select a point on the screen where he wants to write. This is very useful for writing texts on smart phones.
One advantage of touchscreens is that they provide a much clearer output resolution. In a typical computer mouse, the movement of the mouse has to be registered with the precise movement of the trigger (the button). This results in the display of a cursor which vanishes after a few clicks. With touch screens, the movement of the finger is registered continuously and the cursor is shown continuously until a separate motion is taken.
One of the drawbacks of touch screen technology is the possibility of it being affected by electromagnetic radiation. Some devices use electromagnetic active surfaces that emit this radiation. Examples are cell phones that use resistive or liquid crystal displays. In the future, a technology known as capacitive touch screen technology will eliminate the need for active surfaces. With the elimination of the surface acoustic wave, the electrical signals produced by the device will no longer be susceptible to electromagnetic radiation. Some companies are working on capacitive touch screen technology but progress is slow in developing this kind of technology.
Touch screen technology is certainly changing our world. It is providing more convenience to users and manufacturers. As technologies change, touch screens will become more common in electronic devices like laptops, iPhones, and televisions.