Saturday, November 27, 2010

Touchscreen



Touchscreen 1
     It's really common nowadays to see touchscreen gadgets roaming around us very often. The touchscreen concept was previously seen in movies where high tech gadgets were being used by professionals. The touchscreen seems to be really attractive and interactive way of communicating with daily things. Ever wondered how this technology works. So let’s explore the concept behind this most popular and cool gadgets technology.
          
             Touchscreen basically comprises of a touchable surface and an electronic device on which the operation or touch gestures are to be performed. The device, on which we touch, is made of glass beneath it there are many operating layer which we will discuss in later in this article, continuously scans for any touching activity happening over its surface. The touchscreen also have some sensors for specific detection methods, sometimes it detects hand or fingers only, sometimes pen or other object like stylus are being used for better accuracy. For using touchscreen you don’t have to hold any other object or hardware to connect with the device, the system is inbuilt over the screen and this technology increases the interactivity of virtual objects to real ones. Now most of the mobile devices are integrated with this technology, mostly smart phones or high budget devices e.g. Personal Digital Assistants, Satellite navigation devices, Security systems devices, touch surface, now gaming also and many more fields.

           The touch generation started at early as 1971, when the first touch sensor was developed by Doctor Sam Hurst, while he was an instructor at the University of Kentucky. This was just starting of this technology, though the sensor made then was not that cool as it is now. But it proved a milestone in evolution of touch screen. Later on at 1974 Sam Hurst made a true touch screen based on transparent glass surface. Then this evolution just gets on increasing and now its being finding its place everywhere and in nearly every sector this is going to be incorporated in near future.
Touchscreen 2
Construction 
                             As summarized above there are many ways to build on an Touch Screen. The basic requirement of an device is , a conductive coating polyester layer, Adhesive spacer, Glass layer coated with transparent conductive metallic layer, Adhesive layer on the backside of the glass for mounting.
There are various technologies used for touch screen mechanism. 
Resistive Touchscreen 
                             In this type of Touch Screen Mechanism, the screen consists of two thin metallic layers, with a small gap between them. When somebody press the upper layer the upper layer at that point came in contact with lower conducting metallic layer, which is tracked by sensor as an touch activity through variation in voltages and current. 
Surface Capacitance 
                            In this technology one surface is coated with conducting material and other is insulator. A current is applied to conducting part, which results in uniform static field. When we touch our finger over the screen there is capacitive effect observed as our hand/finger act as a conducting material. This change in field is registered at that point and sensing performs the operation. 
Capacitive Sensing 
TouchScreen3
                           In this technology the upper layer is made of glass and coated with a transparent conducting material, when our finger touches the Screen a measurable Capacitive effect is detected, which is basic idea behind this Touch effect technology. 
Surface Acoustic Wave 
                          In this technology ultrasonic waves are passed over a surface where we touch the screen . As we touch the screen some part of the continuous ultrasonic waves get absorbed by our fingers /hands which act as a sensor for the controlling unit to predict where the screen was touched. 
Infrared 
                          In this type of technology the infrared rays are employed to serve the task. A pair of infrared arrays are used in X-Y plane as LED and photo-detector, when the path of these rays is blocked the system tracks the point of contact where the object touch the screen. Most Accurate and also can take pens stylus etc where fingers can’t be used. 
Dispersive Signal Technology 
TouchScreen4
                          In this technology , which is introduced in 2002 uses the Mechanical energy to convert into signals of touch screen, many complex algorithms are employed. Distortion is less. 
Acoustic Pulse Recognition: This system also depends on conversion of mechanical energy, using piezoelectric transducers. The mechanical energy developed is sensed by the vibration produce by the user while touching on the screen.
Touch screen has various application and is really a valuable technology that can server many modern generation purpose . In near future computing world is going to change to lots of dynamic attributes and to huge vastness . 


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