A touch screen or capacitive touch screen is a combination of an input and output unit. The touch screen is generally layered over an image of an information processing device. The screen is often either an LCD LED or OLED display screen while the system is a phone, tablet, or laptop. It is used to control the operation of electronic equipment in much the same way that a keyboard controls the operation of a computer. It works by detecting physical touch on the screen and interpreting that as a request from the user for a particular function.
Capacitive touch screen technology was first developed in 1980 by Jobs Technology. The device consisted of two metal plates having parallel slits at their centres. Pressure was applied with the fingers of one hand on the plates and that was sensed by the electrical charges produced by a combination of electromagnetic induction and the acoustic wave produced by the other hand. The signals produced were then interpreted by the motherboard, which then relayed the data to the various software programs which the device was controlled by.
This was a remarkable advance on a very old form of computing. At the time, the only real touch screen was a stylus on a computer keyboard. A stylus was necessary because you could not just tap the screen like you can today with a finger or a stylus. The stylus was an awkward piece of equipment and the action required strength and care. It also had to be kept at an exact angle so that it would not move when being used.
Today, thanks to advancements in materials and electronics, even this functionality is now available with a touch screen. One such material is an ionic liquid crystal display or LCD, which combines conductive and Capacitive technologies. Instead of using a stylus, which uses mechanical pressure to trigger the computer hardware, the LCD is triggered by the presence of a small electrical charge exchange between the two sides of the display. When the user presses on the display, it is triggered by the electrical current and the motion of the finger, which then transfers the charge to the liquid crystal display screen.
Today, we have touch screens which are made out of many different types of material. One of these is a thin transparent film called “tempered glass”. This is sandwiched between two sheets of transparent material. Touch screens can also be made out of other materials such as sapphire, which is a highly reflective material that reacts to the light. However, the most common materials for touch screens today are conductive and capacitive.
A capacitive touch screen is one where the actual touch of your finger lands on the screen and the finger leaves when it is no longer wanted. Capacitive touch screen technology is quite often referred to as a fingerprint sensor, since it actually works much like a fingerprint too – the one that people use to write the stuff on their hands! This type of technology is used in many different devices such as digital cameras, portable computers and cell phones. One of the advantages of capacitive touch screen technology is that it responds to very quick human movements such as touch or brushing of the finger. The problem is that it can be accidentally triggered when something like a hard tap or a sharp drop hits the display.
A resistive touch screen works on a different principle. Here, a change in the electrical charge is what triggers the response of the device. This means that if you place the device somewhere with a non-permanent electrical charge, it will not respond to any touch. However, if you place the device near a conductive surface, the electrical charge will reactivate. In order for the resistive touch screen technology to work, there must be a way for the electrical charge to change from either a permanent charge such as when a phone is left on overnight, to a temporary one such as when the screen is touched by a user. The change in charge then causes the actuator to trigger the touch screen.
With the advancement of touch screen technology, manufacturers have been able to employ this technology into high tech touch screens, namely the capacitive type. This type has been incorporated into many modern cell phones and portable personal digital assistants. In order to protect your investment in these devices, you should invest in touch screen protectors. These protective guards are made from an extremely hardy material called “transparent film” that is virtually impossible to break or damage.