Dodirnik - touchscreen
Toucscreen dodirnik
Toucscreen, or touch screen technology, is no longer a science fiction story, but something we see every day.
Apple's name has often been associated with the technology, after they introduced the iPhone, a popular mobile phone. Nevertheless, Apple did not invent touch screens, but they are certainly responsible for innovating that technology. Thanks to Apple, the technology has become more widespread and commercially available to more users.
Touch screens - human or those by which you can vacuum with a pen - have been known as technology for about half a century. They were used on ATMs, GPS systems, cash registers, medical monitors, game consoles, phones... - where you will still see them today.
The technology is believed to have been first developed in 1965 by E.A. Johnson, a Royal Radar Establishment officer from the UK. But the tablets, which he patented four years later, could only read one touch at a time and were used to control air traffic almost until 1995.
In 1975, the project PLATO was developed for computer learning, which as an integral part had a terminal equipped with a touchscreen (infrared type). A similar performance appeared in 1983 in one of the first commercial personal computers HP-150, whose 9-inch touchscreen monitor was produced by Sony.
With the development of monitors, it slowly shifted from cathode ray tube technology to liquid crystal monitors, which were also made in touch-sensitive variants. Touch screens have flourished in recent years on mobile phones and tablets, where they represent the basic user interface for work.
Until recently, most touchscreens could only detect touch at one point. This began to change with the development of a type of capacitive display, which has recently been widely used on mobile phones and tablets.
The HP-150 was one of the first commercial touch screen computers. It was produced in 1983. The computer cost $2,795.
The Atari 520ST was the first commercially available POS system, which is still used in restaurants today. That device was invented in 1986 by Gene Mosher.
The first touchscreen phone was introduced in 1992 - the IBM Simon, which was the first "smartphone" (although the term did not exist as such at the time). In the early 1990s, more companies introduced touch-sensitive devices that were actually like PDA.
In 1998, FingerWorks produced a line of multitouch products, including the iGesture Pad and touch stream keyboard. The company was acquired by Apple in 2005.
In 2007, Apple introduced the largest number of innovated touchscreen technologies. The iPhone interface is entirely based on touch screens, including the then infamous virtual keyboard. The iPhone was followed by other devices with touchscreens, such as the iPod Touch and iPad.
A year before the launch of the iPhone, LG boasted of its LG Prada device, which was introduced as the first device with a capacitive touchscreen.
Samsung and Nokia also had similar projects planned, but did not introduce themselves to the public with these products. Nokia dropped production due to fears of cost. Samsung is still struggling with Apple who was the first...
Apple and Samsung are making the same products. Then I buy a Samsung, it's cheaper >>>
Touchscreens passed from phones to game consoles and tablets. In recent years, large companies, such as Apple, Microsoft, Amazon, Samsung, Google have made several devices with touch technology. Today, almost everything you can imagine turns into interactive surfaces: phones, computers, TVs, even desks...
Types of touch screens
There are several types of touch screens according to the way they work.
Resistive screens consist of several layers. The two layers are electrically conductive and are somehow separated from each other (say, tiny non-conductive balls that keep the distance are applied to one of them). By pressing a finger or an object, the conductive layers touch in this place and the electric current flows. Based on this, it is possible to determine the exact location of the touch. However, in this way it is not possible to detect two or more simultaneous touches.
The resistant system allows for very precise operation, but its disadvantage is that it needs to press the surface of the screen relatively hard, while simultaneously dying. Due to its high precision, the resistant system is applied to relatively small screens on mobile devices, and a lot of pressure is achieved by using a pointed stylus pen, which can be made of any material, and is most often made of plastic. The cost of making is relatively low, compared to other touch technologies.
Surface acoustic wave (SAW) screens. Ultrasonic vibrations are released on the surface of these screens, and receivers are located at the edges. When the surface of the screen is touched with a finger or any solid object, the sound is partially absorbed. This change is registered and the location of the touch is determined based on it. These screens are very accurate, but they are also very sensitive to damage and dirt.
There are several types of capacitive touch screens, which differ mainly in whether the screen contains two electrode systems or as another electrode system serves the user's finger. One electrode system consists of a conductive and transparent layer placed on the insulating foil in the form of parallel lines or strips. Each system is connected to an electrical voltage. By touching a finger (where it is not necessary to press) the electrical capacitance in that place changes, which causes the flow of a weak electric current through some of the conductor lines or a change of potential relative to the point of the angle (depending on the type of screen), on the basis of which the point of contact can be determined.
Some types of capacitive screens with two electrode systems allow simultaneous detection of two or more touches, which is used in modern mobile phones and tablets.
Capacitive screens are more complex to make and more expensive than resistive ones . They are sensitive to dirt and grease from the hands, and are also less accurate than resistant types. On the other hand, since the surface does not die, a solid protective layer can be added to them, making them resistant to weather conditions and mechanical damage.
Screens with infrared detection. Although such screens are historically among the oldest, they are still used today – mainly on computer monitors, information displays and cash register monitors in stores. For touch detection, pairs of infrared light-emitting diodes and receivers arranged in sequence on opposite perimeters of the screen so as to give two crossed light beams are used. The touch of a finger (or any object) is easily detected in the place where the corresponding horizontal and vertical rays are obscured by this touch.
No processing of the screen glass itself is required, and neither dust nor greasy prints are bothered because infrared rays do not actually touch the screen itself. Of course, it is not possible to use it in small devices due to the bulking of the system and slightly higher power consumption.
Optical and stress sensors work in a manner similar to optical mice. In the corners of the screen are infrared light sources, and in the corners there are miniature television cameras. The touch of the screen is displayed as a shadow in the field of view of the cameras, which can determine not only the position of the object that touches the screen, but also its size. And this technology is used for larger screen models.
The system was developed in 2002 by 3M and called Dispersive Signal Technology (DST). The specially prepared surface of the screen behaves as a mechanical sensor that measures internal mechanical stresses (compaction, stretching, etc.) when touching and converts this into changes in electrical voltage. These changes are interpreted with the help of a complex algorithm to determine the location and strength of the touch. This technology is insensitive to dust and dirt, and even minor scratches on glass. It is suitable for larger devices.
Screens with piezoelectric converters. A similar technology, only with piezoelectric converters, was designed in 2006 by Tyco International and called Acoustic Pulse Recognition (recognition of acoustic impulses). Sensors with a piezoelectric effect are used located in various places on the screen. When touching, there is mechanical pressure on the sensors, which leads to the formation of an electrical voltage at their ends. Based on the measurement of voltage from all sensors, the position and strength of the pressure are determined. Like the previous ones, this type is suitable for larger screens.
Technologies: resistive touch screen, surface acoustic wave, capacitive touch screen, infrared touch screen, infrared acrylic projection, optical touch screen, dispersive signal technology, acoustic pulse recognition.
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