A Touchscreen is a display which can detect the location of touches within the display area. This allows the display to be used as an input device, removing the keyboard and/or the mouse as the primary input device for interacting with the display's content. Such displays can be attached to computers or, as terminals, to networks. Touchscreens also have assisted in recent changes in the design of personal digital assistant (PDA), satellite navigation and mobile phone devices, making these devices more usable. Global Navigation Satellite System (GNSS is the standard generic term for satellite navigation systems that provide autonomous geo-spatial positioning with global coverage
Touchscreens have become commonplace since the invention of the electronic touch interface in 1971 by Dr. The is a dual-screen Handheld game console developed and manufactured by Nintendo. Samuel C. Hurst. They have become familiar in retail settings, on point of sale systems, on ATMs and on PDAs where a stylus is sometimes used to manipulate the GUI and to enter data. Point of sale or point of service ( POS or PoS) can mean a retail shop, a checkout counter in a shop or the location where a transaction The popularity of smart phones, PDAs, portable game consoles and many types of information appliances is driving the demand for, and the acceptance of, touchscreens. A smartphone is a Mobile phone offering advanced capabilities beyond a typical mobile phone often with PC -like functionality An information appliance ( IA) is an Appliance specializing in information a personal device designed to perform a specific activity such as playing music photography
The HP-150 from 1983 was probably the world's earliest commercial touch screen computer. It actually does not have a touch screen in the strict sense, but a 9" Sony CRT surrounded by infrared transmitters and receivers which detect the position of any non-transparent object on the screen. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with The cathode ray tube (CRT is a Vacuum tube containing an Electron gun (a source of electrons and a Fluorescent screen with internal or Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of For biologic transmitters see Transmitter substance. A transmitter is an electronic device which usually with the aid of an antenna Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation especially visible Light.
Touchscreens are popular in heavy industry and in other situations, such as museum displays or room automation, where keyboards and mouse do not allow a satisfactory, intuitive, rapid, or accurate interaction by the user with the display's content. For other uses of this term see Industry (disambiguation An industry (from Latin industrius, "diligent industrious" "Building automation" can also refer to Build automation, the practice of programmatically Compiling Software programs
Historically, the touchscreen sensor and its accompanying controller-based firmware have been made available by a wide array of after-market system integrators and not by display, chip or motherboard manufacturers. A system integrator is a person or company that specializes in bringing together component subsystems into a whole and ensuring that those subsystems function together a practice With time, however, display manufacturers and System On Chip (SOC) manufacturers worldwide have acknowledged the trend toward acceptance of touchscreens as a highly desirable user interface component and have begun to integrate touchscreen functionality into the fundamental design of their products.
There are a number of types of touch screen technology:
A resistive touch screen panel is composed of several layers. Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is The most important are two thin metallic electrically conductive and resistive layers separated by thin space. Thin-film deposition is any technique for depositing a Thin film of material onto a substrate or onto previously deposited layers When some object touches this kind of touch panel, the layers are connected at certain point; the panel then electrically acts similar to two voltage dividers with connected outputs. In Electronics, a voltage divider (also known as a potential divider) is a simple Linear circuit that produces an output Voltage ( This causes a change in the electrical current which is registered as a touch event and sent to the controller for processing. When measuring press force, it is useful to add resistor dependent on force in this model -- between the dividers.
A resistive touch panel output can consist of between four and eight wires. The positions of the conductive contacts in resistive layers differ depending on how many wires are used. When four wires are used, the contacts are placed on the left, right, top, and bottom sides. When five wires are used, the contacts are placed in the corners and on one plate.
4 wire resistive panels can estimate the area (and hence the pressure) of a touch based on calculations from the resistances.
Resistive touch screen panels are generally more affordable but offer only 75% clarity (premium films and glass finishes allow transmissivity to approach 85%) and the layer can be damaged by sharp objects. Resistive touch screen panels are not affected by outside elements such as dust or water and are the type most commonly used today. Water is a common Chemical substance that is essential for the survival of all known forms of Life.
Surface Acoustic Wave (SAW) technology uses ultrasonic waves that pass over the touch screen panel. A surface acoustic wave ( SAW) is an Acoustic wave traveling along the surface of a material having some elasticity, with an Amplitude that When the panel is touched, a portion of the wave is absorbed. This change in the ultrasonic waves registers the position of the touch event and sends this information to the controller for processing. Surface wave touch screen panels can be damaged by outside elements. Contaminants on the surface can also interfere with the functionality of the touchscreen.
A capacitive touch screen panel is coated with a material, typically indium tin oxide that conducts a continuous electrical current across the sensor. Capacitance is a measure of the amount of Electric charge stored (or separated for a given Electric potential. Uses ITO is mainly used to make transparent conductive coatings for Liquid crystal displays Flat panel displays Plasma displays touch panels The sensor therefore exhibits a precisely controlled field of stored electrons in both the horizontal and vertical axes - it achieves capacitance. The human body is also an electrical device which has stored electrons and therefore also exhibits capacitance. When the sensor's 'normal' capacitance field (its reference state) is altered by another capacitance field, i. e. , someone's finger, electronic circuits located at each corner of the panel measure the resultant 'distortion' in the sine wave characteristics of the reference field and send the information about the event to the controller for mathematical processing. Capacitive sensors can either be touched with a bare finger or with a conductive device being held by a bare hand. Capacitive touch screens are not affected by outside elements and have high clarity.
An infrared touch screen panel employs one of two very different methods. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of One method uses thermal induced changes of the surface resistance. This method is sometimes slow and requires warm hands. Another method is an array of vertical and horizontal IR sensors that detect 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. A strain gauge (alternatively strain gage) is a device used to measure the strain of an object This technology can also measure the Z-axis. Typically used in exposed public systems such as ticket machines due to their resistance to vandalism. Vandalism is the behaviour attributed to the Vandals in respect of Culture: ruthless Destruction or spoiling of anything beautiful or Venerable
A relatively-modern development in touch screen technology, two or more image sensors are placed around the edges (mostly 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. This technology is growing in popularity, due to its scalability, versatility, and affordability, especially for larger units.
Introduced in 2002, this system uses sensors to detect the mechanical energy in the glass that occur due to a touch. In Physics, mechanical energy describes the Potential energy and Kinetic energy present in the components of a mechanical system. 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 styli. A downside is that after the initial touch the system cannot detect a motionless finger.
This system uses more than two piezoelectric transducers located at some positions of the screen to turn the mechanical energy of a touch (vibration) into an electronic signal. This signal is then converted into an audio file, and then compared to preexisting audio profile for every position on the screen. This system works without a grid of wires running through the screen, the touch screen itself is actually pure glass, giving it the optics and durability of the glass out of which it is made. It works with scratches and dust on the screen, and accuracy is very good. It does not need a conductive object to activate it. It is a major advantage for larger displays. As with the Dispersive Signal Technology system, after the initial touch this system cannot detect a motionless finger.
This optical system works by using the principle of total internal reflection to fill a refractive medium with light. When a finger or other soft object is pressed against the surface, the internal reflection light path is interrupted, making the light reflect outside of the medium and thus visible to a camera behind the medium. 
Developed by Zachary Scott Carpenter as a more robust alternative to Frustrated Total Internal Reflection (FTIR). Diffused Laser Imaging (DLI) uses the same software and imaging system as FTIR. Instead of the light coming from inside the screen it comes from diffused laser light being conducted through human flesh and onto the diffuser of the screen. A two dimensional plane of laser light is emmitted directly over a rigid screen (diffused glass). When a human finger breaks this plane of laser light the light is diffused by the finger and thus passes from the intersection point through the finger and down to the diffuser of the rigid screen. This system works just a well as FTIR but is not vulnerable to smudges or dirt on the screen. Furthermore most all multi touch functions can be achieved with only two laser line sources versus the many light sources required to internally illuminate the internal portion of a FTIR screen. DLI can also be used on most any kind of flat monitor by placing one or two position sensing cameras out in front of the display. In this case the cameras pick up the diffused finger tips as blobs of light instead of dots as viewed from the back side.
Virtually all of the significant touchscreen technology patents were filed during the 1970s and 1980s and have expired. Touchscreen component manufacturing and product design are no longer encumbered by royalties or legalities with regard to patents and the manufacturing of touchscreen-enabled displays on all kinds of devices is widespread.
The development of multipoint touchscreens facilitated the tracking of more than one finger on the screen, thus operations that require more than one finger are possible. These devices also allow multiple users to interact with the touchscreen simultaneously.
With the growing acceptance of many kinds of products with an integral touchscreen interface the marginal cost of touchscreen technology is routinely absorbed into the products that incorporate it and is effectively eliminated. In Economics and Finance, marginal cost is the change in Total cost that arises when the quantity produced changes by one unit As typically occurs with any technology, touchscreen hardware and software has sufficiently matured and been perfected over more than three decades to the point where its reliability is unassailable. As such, touchscreen displays are found today in airplanes, automobiles, gaming consoles, machine control systems, appliances and handheld display devices of every kind.
The ability to accurately point on the screen itself is taking yet another step with the emerging graphics tablet/screen hybrids. A graphics tablet/screen hybrid (or tablet/LCD hybrid Tablet LCD Monitor) is a Graphics tablet that incorporates an LCD into the tablet itself allowing the user
An ergonomic problem of touchscreens is their stress on human fingers when used for more than a few minutes at a time, since significant pressure can be required and the screen is non-flexible. This can be alleviated with the use of a pen or other device to add leverage, but the introduction of such items can sometimes be problematic depending on the desired use case (for example, public kiosks such as ATMs). Also, fine motor control is better achieved with a stylus, a finger being a rather broad and ambiguous point of contact with the screen.
Yet all of these ergonomic issues can be bypassed simply by using a different technique, provided that the user's fingernails are either short or sufficiently long. Rather than pressing with the soft skin of an outstretched fingertip, the finger is curled over, so that the top of the forward edge of a fingernail can be used instead. (The thumb is optionally used to provide support for the finger or for a long fingernail, from underneath. ) The fingernail's hard, curved surface contacts the touchscreen at a single very small point. Therefore, much less finger pressure is needed, much greater precision is possible (approaching that of a stylus, with a little experience), much less skin oil is smeared onto the screen, and the fingernail can be silently moved across the screen with very little resistance, allowing for selecting text, moving windows, or drawing lines. (The human fingernail consists of keratin which has a hardness and smoothness similar to the tip of a stylus, and so will not typically scratch a touchscreen. A nail is a horn -like structure at the end of an animal's Finger or Toe. Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds A stylus (plural styli or styluses) is a Writing utensil. The word is also used for a computer accessory ( PDAs) ) Alternately, very short stylus tips are available, which slip right onto the end of a finger; this increases visibility of the contact point with the screen. Oddly, with capacitive touch screens, the reverse problem applies in that individuals with long nails have reported problems getting adequate skin contact with the screen to register keystrokes (note that styli do not work on capacitive touch screens nor do gloved fingers).
This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL. A graphics tablet (or digitizing tablet, graphics pad, drawing tablet) is a computer Input device that allows one to hand-draw images and graphics A light pen is a Computer Input device in the form of a light-sensitive wand used in conjunction with a the computer's CRT TV set or monitor Multi-touch (or multitouch) denotes a set of Interaction techniques which allow computer users to control graphical The is a dual-screen Handheld game console developed and manufactured by Nintendo. A Tablet PC is a Notebook or slate-shaped Mobile computer, equipped with a Touchscreen or Graphics tablet/screen hybrid technology which allows A touchpad (also trackpad) is a Pointing device consisting of specialized surface that can translate the motion and position Dynamic Device Mapping is a robust technology for USB KVM switches implemented to replace standard USB keyboard and mouse emulation The Free On-line Dictionary of Computing ( FOLDOC) is an online searchable encyclopedic Dictionary of Computing subjects The GNU Free Documentation License ( GNU FDL or simply GFDL) is a Copyleft License for free documentation designed by the Free Software