Touch screen technology and types

Touch screen also called touch panel. It is an inductive LCD device which can receive input signals. It is an important source of input device and output device normally layered on the top of an electronic visual display of an information processing system. A user can give input or control the information processing system through simple or multi-touch gestures by touching the screen. The user can use the touch screen to react to what is displayed and to control how it is displayed.

In terms of inductive mode, touch screen can roughly classified into resistive, capacitive, infrared and ultrasonic type, among which resistive and capacitive type are the most promising in current market prospect, while other technology is hard to catch up in short term.

Resistive touch screen: pros & cons

Resistive touch screen commonly is known as soft screen. It is usually used in phone with Windows Mobile system. Resistive touch screen phone adopts pressure induction, which enables us to operate with a finger, gloved hand, stylus or any objects squeezing on the screen. It is the measure of the resistance of the display at point of contact, which leads to get an accurate measurement of the touch position.

1. Pros of Resistive Touch screen

● Low production cost

● High resistance to dust and water

● Best used with a finger, gloved hand or stylus

● Best suited for handwriting recognition

2. Cons of Resistive Touch screen

● Not too sensitive, you have to press down harder

● Poor contrast because of having additional reflections from extra layer of material placed over the screen

● Not support multi-touch

Capacitive touch screen: pros & cons

Capacitive touch screen commonly is known as hard screen. Capacitive touch screen phone adopts electrostatic induction. Human body is an electrical charge conductor. When a finger touches the glass of the capacitive surface, it changes the local electrostatic field. The system continuously monitors the movement of each tiny capacitor to find out the exact area where the finger touches the screen. M8, M9, NOKIA X6, HTC HD2, iPhone, G1, MOTO, etc. these smartphones are using the touch screen.

1. Pros of Capacitive Touch screen

● Because of capacitive touch screen has glass layer instead of plastic, it looks brighter and sharper

● High touch sensitive and doesn’t need a stylus

● Supports multi-touch

2. Cons of Capacitive Touch screen

● Because of the technology is dependent on the conductive nature of human body, it doesn’t work if the user is wearing gloves

● Because of having a complex structure, these are quite expensive

● Glass is more prone to breaking

Multi-touch

Multi-touch is technology achieved by human-computer interaction technology and hardware devices. It can conduct human-computer interaction operation in the condition of lacking of traditional input devices, like mouse, keyboard, etc. Different models of phone supports different points of contact with the surface. Smartphones can generally support 2 - 5 points of contact, ranging from two to ten points of contact. The point of contact can be modified, so it’s better to have two enough since you do not play big games, otherwise, the phone will gets stuck.

Non-touch screen

This type of phone is keypadded phone. Users can operate through keypad. At present, these phones only be popular among the elders.