Touchscreen is an electronic device that has a double function, namely the output of (a medium to display the UI) and the input command (media advising what to do). When this type of touchscreen display is widely used in laptops, PDAs, mobile phones, digital cameras, Mp3 players, and even a photo copy machine. Android is one of them, most of the android device using a touch-screen media display.
History of the touch screen
In 1971, the first "Touch Sensor" was developed by Doctor Sam Hurst (founder Elographics) as well as an instructor at the University of Kentucky. These sensors are called "Elograph," and has been patented by the University of Kentucky Research Foundation. "Elograph" is not transparent like modern touchscreens, however elograph has been a significant milestone in touchscreen technology. In 1974 The real first touchscreen equipped with transparent surfaces was developed by Doctor Sam Hurst and Elographics. In 1977 Elographics developed and patented by a five-wire resistive technology, which is the most popular touchscreen technology used today.
Touchscreens eventually become commonplace in everyday life. The company uses a touch screen kiosk system in the regulation of retail sales and tourism, sales center, ATM, and PDAs, where the stylus is sometimes used to manipulate the GUI and to enter data. Popularity of smart phones, PDAs, portable game consoles and various types of information appliances has boosted demand and acceptance of touchscreens.
HP-150 from 1983 has been one of the earliest computers in the world of commercial touchscreen. Does not have a touchscreen in a narrow sense, but it has a CRT tube Sony 9 "surrounded by infrared transmitters and receivers, which detect the position of each non-transparent objects on the screen.
Originally the original touchscreens could only sense one point of contact at a time, and have little ability to sense how hard one's touch. Has now begun to change with the commercialization of multi-touch technology.
Tablet PC initiated by apple computer and followed by the famous brands of the world has made multi-touch touchscreen becomes the primary interface with a variety of capabilities that it provides.
How it Works Touchscreen
Simply put, the workings of a touch screen touch input is received to translate into the position coordinates on the screen, and then execute certain commands that correspond to the image on the screen is touched. Actually it is not the image that triggers the execution of commands, but the coordinates of the trigger sentuhanlah execution. So the logic is roughly like this: "If the coordinates = (x, y) then the command to do X".
Various Kinds Touchscreen
Although at first glance all look the same touch screen, but the technology used was different. Various kinds are:
A. Resistive Touchscreen
As the name implies, the touch screen utilizes the difference in the value of resistance (resistance) to determine the position coordinates of the touch. Resistive system consists of glass coated with two layers of metal materials. The first layer of metal capable of delivering electricity, which can not be. 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 the electrical current.
Both 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. The second layer on top of it there is a scratch-resistant coating. It was where the user's touch screen to perform an action. When the monitor is turned on, electrical current flows between the two metal layers. When touched, the second metal layer is in contact with each other resulting in a change in resistance in the area is touched. Change is then recorded and the coordinates of the touch was determined.
When there is a touch of the two layers will be forced to come into contact with 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 reference current value is then reported to the controller for the process further.
Touch information were processed mathematically by the controller so as to produce an accurate and position coordinates of the touch. Then the information is integrated with another program so that it becomes easy to use application.
Screen with this technology has the highest image clarity by 75% only, so 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 on the outside such as dust or water, but will respond to all of touch about it, either using your fingers directly or using other objects such as a stylus. It is used for industrial purposes in the world such as in factories, laboratories, and more.
The screen is how it works should be suppressed, can use your finger or any object which is emphasized on the screen. Drawback to this is if the screen is placed dikantong (especially pants pocket), can be depressed, press and caused the screen to be easily damaged because it is often depressed.
Indoor: very good
Outdoor: less than optimal
Its features are included stylus in the package with his cell phone. Choose a container that uses a flip model, so the screen can be protected from pressure. Vice versa is not recommended to use the HP models pouch container.
B. Capacitive Touchscreen
The touch screen utilizes the difference in capacitance value to determine the position coordinates of the touch. Unlike the resistive, capacitive system only has a layer of glass placed on the monitor. At the time of the layer that stores electrical charge that is touched, a little electrical charge is transferred to the finger penyentuh. As a result, the electric charge in the layer was reduced. Was then measured by a reduction in circuits located at each corner of the monitor. Each circuit provides a different value, depending on the position of the touch. After measurement is complete, the computer determines the position of the touch based on differences in the values given by the circuit.
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 is used as reference value.
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 these events 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 point sudur on touchscreen panel as a reference. When the calculation result is obtained, then the coordinates and the position of the touch can be in the know were well. Finally, information from these will be integrated with other programs to run an application.
The new capacitive touchscreen can work against him if it touches a conductive object CAME from Such as a finger. Display screen has a clarity of up to about 90%, making it Suitable for use in a variety of purposes in the general public interactions Such as in restaurants, electronic kiosks, Point Of Sales locations, etc ..
Should the touch of a finger, can not use other objects (nails, stylus, etc.). Because these screens work by using an electrical charge That is your body we. Model of a capacitive touch screen is almost no significant weakness, Because this screen is the latest development to replace the resistive screen.
Indoor: very good
Outdoor: very good
Advantage: the display is not affected by the type of pressure, so even if HP put dikantong not a problem. The use of container pouch models can be Considered safe. Its features are not included stylus in his cell phone package.
C. Surface Acoustic Wave Touchscreen
Surface acoustic wave touchscreen using a transducer to receive and transmit electrical signals. In Addition to the transducer, the system also has a reflector is used to deflect That the waves transmitted by a transducer to another transducer. Transducer receives the signal can Provide information on when it receives a wave disturbed by touch. He will also give a touch to the right position.
Touchscreen technology utilizes ultrasonic waves to detect events at the surface of the screen. On the 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 on 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 hindered by the hand, stylus, keyboard, and more. The touch had made changes in the transmitted waveform.
Changes that occur ultrasonic waves received by the receiver and then 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 the touch of this course is the data on your hands that touch the ultrasonic signal. If this is done continuously and there are many ultrasonic wave sensor that touches on the media, then be a touchscreen device that you can use.
This technology does not use a metallic coating material but rather a layer of glass, the touchscreen display of this type could carry up to 90 percent light, 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 is no coating that can be damaged when the touch, when exposed to water, oil, dust, and more.
The disadvantage is the performance of the touchscreen can be interrupted by elements such as dust, water, and other solid objects. There is little dust and debris that stick on it then touchsreen can detect it as a touch.
Outdoor: less than optimal
D. SurePress Touchscreen
SurePress touch screen is the fiture which today is more facilitated in the operation of mobile phone by touching the screen to operate like a punch to the menu selected by pressing the desired on-screen menu. The touch screen of this type used by the vendor or developer of the RIM BlackBerry.
Technology touch-screen button that has the effect of this type bouncy (haptic feedback) as the usual physical, can be said is a combination of capacitive and resisitive because it can be smooth like a capacitive tap and capable in the press to the effect like the resisitive
Form a very unique SurePress touch screen, innovative touch screen with SurePress well, allowing the two thumbs were still dancing and give effect to push the button on the screen phone, But SurePress is not followed by a screen that is responsive to the touch. To download a screen zoom, for example, often have to perform a new touch screen 2-3 times to zoom as expected. This differs from the android, which is very nice virtual buttons to scroll or zoom the screen.
E. multi Touchscreen
Multi touch screen is the development of touch screen technology that already exists. Of the meaning of the word "multi" which means a lot, already 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.
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.
This type of multi-touch screens are often used on android devices, so you can operate your android you can feel comfortable, especially when you play a game on your android, multi touch very involved.
Anything that affects the touch point on the multi touch screen android?
Sensor >>>> found on the screen (Hardware)
Sensors on the touch screen which greatly affects the amount detected, one can detect two touch points, 4 points touch, or even 10 touch points simultaneously. Almost all sophisticated Android smartphone supports multi-touch up to 10 touch points.
Factors >>>> operating system firmware (Software)
Firmware jg factors affect the number of touch which can be detected by the screen. For example, Eclair Android OS does not support multi touch on the device, but when upgraded to version Froyo the device so it can detect two touches.
How do I find out the number of touch points on my android?
Of course by doing the test, some applications store in google play are available, one with MultiTouch Tester application which you can download by clicking the image below
F. floating Touchscreen
Floating touchscreen is the development of touch screen technology that already exists, one that uses the products from Sony, the Xperia Sola. Floating Touch technology can not be used in all functions of the Smart Phone Xperia Sola, but only in the web browser menu. Users can browse web pages without actually touching the screen.
Floating Touch is an innovative invention that combines capacitive touchscreen technology (I have explained at the top of this article) that is currently widely used.
In a capacitive touchscreen display, of course, required conductivity. There are two different display types if classified based on the received signal strength. The first is a display of self capacitance with stronger signals. This type of screen can detect your finger from a distance of 0.79 inches. However, capacitive touchscreen display technology of this type does not support multi touch. The second type of screen is a capacitive multi-screen multi-touch support. However, because they have to divide the received signal, the signal strength of each finger is reduced. As a result, you can not 'cast' your finger over the touchscreen display
By combining the two types of capacitive touchscreen display, finally succeeded in inventing new technologies Floating Touch, by increasing the capacitive touch sensor and touch lower threshold limit, it would be possible to distinguish between normal Floating Touch by touch.
However, to use the latest technology invention Floating Touch This, it must use an additional application. On Sony Xperia Sola, the latest technology can only be used on the browser and the live wallpaper.
For another thing about floating touchscreen, the less I understand how to work more, because I have never met in person, but I find this article on floating touch from some existing source
How to care for the touch screen or touchscreen phone
A. Use a screen protector or a scratch-resistant plastic on the phone screen.
2. Remove your phone from objects that contain a magnetic field such as radio, television, and other objects that contain magnets.
3. Keep the LCD screen is not in a dirty, dirty, and if the screen is clean by using a tissue or a soft cloth.
4. Use index finger to use the screen, do not use nails to wipe the screen when you're using because it will lead to scratched screens.
5. Avoid exposure to direct sunlight, because it will damage the quality of the LCD.
6. Do not press the screen too hard, just tap the screen naturally.
7. Avoid places such as narrow and pressed jeans pocket, because it will quickly damage the LCD screen if it is too often the pressure.
View the Original article