How the Touchscreen Works

Prestige was make the name of the touchscreen (touchscreen) became popular and well known today. At this time we will discuss how the workings of the touch screen that can make an item have a high prestige in the presence of such features.

Recognize how to work the touch screen can help to treat and differentiate the types of touch screens on mobile phones of today. There are four types, namely, resistive, capacitive, surface acoustic wave systems and multi touchscreen.

1. Resistive Screen
System resistive screen is coated by a thin layer of colored metallic conductive and resistive to electrical signals. The purpose of the conductive layer is a layer that is easy to conduct electrical signals, while the resistive layer is a layer that holds an electrical current.
These two layers are separated by a separator transparent spots, so that this layer must be separated from each other in normal circumstances. On the conductive layer is also in charge of electric current flow as the reference current.

When there is a touch, this 2 layer will be forced to directly contact each other physically. Because of the contact between the conductive and resistive layers there will be interference with the reference electric current.

The effects of these disorders on the conductive layer is going to change electrical currents in response to a touch event. Change the value of the reference current is then reported to the controller for the process further.

Touch information was processed mathematically by the controller so as to produce an accurate coordinates and the position of the touch. Then the information is integrated with other programs so that it becomes an application easy to use.

Screen with this technology has the highest image clarity by 75% only, so that the monitor will seem less clear. Touch sensors of this type are very vulnerable and weak to touch objects that are somewhat sharp.

This technology will not be affected by other elements outside such as dust or water, but will respond to all touch about it, either using your fingers directly or using another object such as a stylus. It is used for industrial purposes in the world such as in factories, laboratories, and many more.

Simplified definition:
The screen is how it works should be suppressed, can use your finger or any object on the screen to press. The downside is if the screen is placed on pocket (especially pants pocket), can be depressed, and caused the screen to be easily damaged because it is often depressed.

Indoor : very good
Outdoor : less than optimal


2. Capacitive Screen
Capacitive system has a coating which is the key of how it works, that is a wrapper which is capacitive in the entire surface. Touchscreen panel is equipped with a coating made ​​from indium tinoxide which could continue for an electric current is continuous, then directed to the sensor.

This layer can utilize the capacitive nature of the hand or the human body, and therefore this layer is employed as a touch sensor in this type of touchscreen. When the layers are in normal status (without any touch of the hand), the sensor will be given an electric current value is used as reference.

Capacitive Screen Tech

When your fingers touch the surface of this layer, then the reference value is changed because there are electric currents that change the entry to the sensor. Information from this incident in the form of electrical current will be received by the sensor to be transmitted to a controller. Position calculation process will start here.

This calculation uses the position of the four side points touchscreen panel as a reference. When the results of the calculation is obtained, then the coordinates and the position of the touch can be designated in the know with the good. Finally, information from these positions will be integrated with other programs to run an application.

The new capacitive touchscreen can work if it touches against him came from a conductive object such as a finger. Display screen has a clarity of up to about 90%, making it suitable for use in a variety of purposes interactions in the general public such as in restaurants, electronic kiosks, the location of Point Of Sales, etc..

Simplified definition:
Must be with the touch of a finger, can not use other objects (nails, stylus, etc.). Because these screens work by using an electrical charge from our body. Capacitive touch-screen model is almost no significant weakness, because this screen is the latest development to replace the resistive screen.

Indoor: very good
Outdoor: very good

3. Surface Acoustic Wave System
Touchscreen technology utilizes ultrasonic waves to detect events at the surface of the screen. Inside this touchscreen monitor, there are two transducers, sender and receiver of ultrasonic signals.

Also equipped with a reflector which also serves as a deterrent so that ultrasonic waves remain on the monitor screen area.

Both transducers are mounted in all four sides, two vertical and two horizontal. When it touched the touchscreen panel, there is a part of the wave is absorbed by touch, such as hindered by the hand, stylus, keyboard, and more. The touch had made ​​changes in the waveform emitted.

"Surface Acoustic Wave Screen" Diagram

Changes in ultrasonic waves that occur later accepted by the receiver and translated into electrical pulses. Further information had been turned into a form of touch data to be forwarded to the controller for further processing.

Data generated from this touch of course is data about the position of your hands that touch the ultrasonic signal. If this is carried out continuously and there are a lot of the ultrasonic wave sensor on the media it touches, so be a touchscreen device that you can use.

This technology does not use a metallic coating material but rather a layer of glass, the appearance of the touchscreen display able to continue this kind of light up to 90 percent, making it much clearer and brighter than the Resistive touchscreen. Without the sensor layer also makes the touchscreen of this type become stronger and more durable because there will be no layers that can be damaged when the touch, when exposed to water, oil, dust, and more.

The disadvantage of this touchscreen performance can be plagued by elements such as dust, water, and other solid objects. There is very little dust or other object attached to it then touchsreen can detect it as a touch. Touchscreen type is suitable for use on computer training room, the room needs to display information in a very clear and sharp and the presentation in the room.

4. Multi Touchscreen
Multi touch screen is the development of touch screen technology that already exists. From the meaning of the word "multi" which means a lot, have seen that the advantage of the touch screen can be touched by more than one finger. Multi-touch screen is capable of being touched by the finger of dozens of different people simultaneously.

Samsung UD MultiTouchScreen Tech

Multi-touch screen can be used to enlarge, shrink, change position, and move the position of objects on the screen such as images or games. Multi-touch screen is commonly used in cell phones, computers, MP3 players, and so on. 

So, that is a little information about touch sreen, may be taken advantage of a little of this science.