Which technology is used in touchscreen mobile

Now we not only take touch input for granted, we expect to be able to use multitouch using more than one finger on the screen at a time and gestures as well. What made this touch screen revolution possible, and where is it likely to take us? To begin with, not all touch is created equal. There are many different touch technologies available to design engineers. According to touch industry expert Geoff Walker of Walker Mobile , there are 18 distinctly different touch technologies available.

Some rely on visible or infrared light; some use sound waves and some use force sensors. They all have individual combinations of advantages and disadvantages, including size, accuracy, reliability, durability, number of touches sensed and -- of course -- cost.

As it turns out, two of these technologies dominate the market for transparent touch technology applied to display screens in mobile devices. And the two approaches have very distinct differences.

One requires moving parts, while the other is solid state. One relies on electrical resistance to sense touches, while the other relies on electrical capacitance. One is analog and the other is digital.

Analog approaches measure a change in the value of a signal, such as the voltage, while digital technologies rely on the binary choice between the presence and absence of a signal. Their respective advantages and disadvantages present clearly different experiences to end users. All of these processes happen simultaneously in a matter of seconds completely unbeknownst to the user.

Resistive touchscreens are great for a variety of applications and users. Resistive touchscreens also come at a much lower price point than its contemporaries, but there are some drawbacks to this. If cost is the main driving force behind your touch technology buying decision, however, then the resistive touchscreen is the right choice for you.

Infrared touchscreens come in at the highest price point, but they also have a lot of advantages, one of which is the ultra-crystal clear image quality and clarity. The way it works is that infrared receivers and light emitters produce a group of invisible light beams throughout the screen, which eliminates the need for a protective layer.

The lack of a protective screen results in the pristine crystal clear picture quality. Every time a point of contact is made either by an object or human finger, the light beams are interrupted. The device automatically recognizes and reacts to the directive given by the point of contact. Despite all of these great features, there are a few glaring disadvantages that are hard to ignore, especially since infrared touchscreens are the most expensive out of all of the displays mentioned here.

Infrared touchscreens are incredibly sensitive to all points of contract, including dirt, dust, and grease buildup on the screen. In order for the screen to work accurately, it has to be perfectly clean at all times. Coming too close to the screen will activate its sensors, causing it to immediately react to any accidental touches.

Surface Acoustic Wave SAW touchscreens are made up of a variety of piezoelectric transducers which convert different amounts of pressure into electrical signals and receivers that are located along the sides of the screen.

The piezoelectric transducers and the receivers work in tandem to create an unseen grid system of ultrasonic waves across the surface panel. The body beautiful. Red tape, white lies. Speculative science.

This sceptred isle. Root of all evil. Ethical conundrums. This sporting life. Stage and screen. Birds and the bees. In regular mobile phones, a keypad type of device is used, which is mounted separately from the screen of the cellphone.

Whereas in touch screen cellphones, a touch screen is a cellphone display screen that also acts as an input device.