The Computer Revolution/Peripherals/Pointers

Joy-stick
A Joystick is a general control device that transmits it's angle with two or three dimensions to a computer. It consists of a handheld stick that pivots and how it works is similar to that of a mouse. It also consists of a base and a trigger. You connect the Joystick into the "Joystick input" of your computer for use. They are used usually for games but also are used for things like cranes and trucks. They were especially popular in the mid-90's for control games like Flight Simulator, a flying game.A joystick is very popular and even today some kids use joysticks to play there everyday game.(pac man)etc.

Light-pen
An input device that utilizes a light-sensitive detector to select objects on a display screen. A light pen is similar to a mouse, except that with a light pen you can move the pointer and select objects on the display screen by directly pointing to the objects with the pen.

Touch-screen
How to use a touch screen; Touch screen/Pads are devices that are used by a person by simply touching the screen and controlling the mouse with his or her fingers tips along the screen. End users are able to scroll up and down and side to side to find information they are looking for. Touch Pads usually come in the shape of a rectangle and are becoming very common stand alone devices.



Touch Screens are display screens that are sensitive to the touch of a finger or a pointing device. This removes the keyboard and/or the mouse as the primary input device for interacting with the display's content. A basic touchscreen has three main components: a touch sensor, a controller, and a software driver. A touch screen sensor is a clear glass panel with a touch responsive surface. The controller is a small PC card that connects between the touch sensor and the PC. The driver is a software update for the PC system that allows the touchscreen and computer to work together. Touchscreen computer systems are perfect for multi-media applications, kiosks, restaurants, computer based training, ATMs (automated teller machines), PDAs (personal digital assistants), retail settings, handicapped, real-estate, executive information systems, and much more. There are a number of types of touch screen technology:  A resistive touch screen panel is coated with a thin metallic electrically conductive and resistive layer that causes a change in the electrical current which is registered as a touch event and sent to the controller for processing. Surface wave technology uses ultrasonic waves that pass over the touch screen panel when the panel is touched. A capacitive touch screen panel is coated with a material, typically indium tin oxide that conducts a continuous electrical current across the sensor. Capacitive sensors must be touched with a conductive device being held by a bare hand or a finger, unlike resistive and surface wave panels that can use anything that can point, such as a finger or stylus. An infrared touch screen panel employs one of two very different methodologies. One method used thermal induced changes of the surface resistance. This method was sometimes slow and required warm hands. Another method is an array of vertical and horizontal IR sensors that detected the interruption of a modulated light beam near the surface of the screen IR touch screens have the most durable surfaces and are used in many military applications that require a touch panel display. In a strain gauge configuration the screen is spring mounted on the four corners and strain gauges are used to determine deflection when the screen is touched. Optical Imaging: A relatively-modern development in touch screen technology, two or more image sensors are placed around the edges (usually the corners) of the screen. Infrared backlights are placed in the camera's field of view on the other sides of the screen. A touch shows up as a shadow and each pair of cameras can then be triangulated to locate the touch and Dispersive Signal Technology: is the newest technology, introduced in 2002. It uses sensors to detect the mechanical energy in the glass that occur due to a touch. Complex algorithms then interpret this information and provide the actual location of the touch. The technology claims to be unaffected by dust and other outside elements, including scratches. Since there is no need for additional elements on screen, it also claims to provide excellent optical clarity. Also, since mechanical vibrations are used to detect a touch event, any object can be used to generate these events, including fingers and styluses. The technology is still quite new and is not currently widely available. http://en.wikipedia.org/wiki/Touchscreen http://encyclopedia.thefreedictionary.com/Touch+screen