Types of Touch Screens
The fashion for touch screens literally swept the whole world of high technology. Now a rare cell phone or player does without a “touchscreen”, and the general scope of touch-sensitive displays is completely unlimited. It is these facts that made us tell you about the types of touch screens and their applications.
The touch screen is a device for input and output of information through a touch-sensitive display and gestures. As you know, the screens of modern devices not only display an image, but also allow you to interact with the device. Initially, familiar buttons were used for such interaction, then the no less well-known mouse manipulator appeared, which greatly simplified the manipulation of information on the computer display. However, the “mouse” for work requires a horizontal surface and is not very suitable for mobile devices. This is where an addition to the regular screen comes to the rescue – Touch Screen, which is also known as Touch Panel. That is, in fact, the touch element is not a screen – it is an additional device installed on top of the display from the outside, protecting it and serving to enter the coordinates of touching the screen with a finger or other object.
Today, touch screens are widely used in mobile electronic devices. Initially, the touchscreen was used in the design of handheld personal computers (PDAs, PDAs), now communicators, mobile phones, players and even photo and video cameras hold the lead. However, the technology of controlling a finger through virtual buttons on the screen turned out to be so convenient that almost all payment terminals, many modern ATMs, electronic information kiosks and other devices used in public places are equipped with it.
Touch screen laptop
It should be noted laptops, some models of which are equipped with a rotatable touch screen, which gives the mobile computer not only broader functionality, but also greater flexibility in managing it on the street and on weight.
Unfortunately, there are not many similar laptop models, popularly referred to as “transformers”, but they are.
In general, the touch screen technology can be described as the most convenient when you need instant access to control the device without preliminary preparation and with amazing interactivity: the controls can change each other depending on the function being activated. Anyone who has ever worked with a touch device understands the foregoing.
Types of the Touch Screen monitor
In total, several types of touch panels are known today. Naturally, each of them has its own advantages and disadvantages. We distinguish the main four designs:
- Projected Capacitive
- With the definition of surface acoustic waves
In addition to these screens, matrix screens and infrared are used, but due to their low accuracy, their scope is extremely limited.
Resistive touch screen monitor
Resistive touch panels are among the simplest devices. At its core, such a panel consists of a conductive substrate and a plastic membrane with a certain resistance. When a membrane is pressed, it closes with the substrate, and the control electronics determines the resistance that arises between the edges of the substrate and the membrane, calculating the coordinates of the pressure point.
The advantage of a resistive screen monitor is its cheapness and simplicity of the device. They have excellent resistance to pollution. The main advantage of resistive technology is its sensitivity to any touch: you can work with your hand (including gloves), a stylus (pen) and any other hard blunt object (for example, the upper end of a ballpoint pen or the corner of a plastic card). However, there are also quite serious drawbacks: resistive screens are sensitive to mechanical damage, such a screen is easy to scratch, therefore, a special protective film protecting the screen is often purchased. In addition, resistive panels do not work very well at low temperatures, and also have a low transparency – they pass no more than 85% of the display’s luminous flux.
Touch Screen Pen Usage
- Cell Phones
- POS terminals
- Tablet pc
- Industry (control devices)
- Medical equipment
Capacitive touch screen monitor
The capacitive touch screen technology is based on the principle that a large-capacity object (in this case a person) is able to conduct electric current. The essence of the capacitive technology is to apply an electrically conductive layer to the glass, and a weak alternating current is applied to each of the four corners of the screen. If you touch the screen with a grounded, large-capacity object (finger), current will leak. The closer the touchpoint (and therefore leakage) to the electrodes in the corners of the screen, the greater the leakage current, which is recorded by the control electronics, which calculates the coordinates of the touch point.
Capacitive screens are very reliable and durable, their resource is hundreds of millions of clicks, they perfectly resist pollution, but only those that do not conduct electric current. Compared to resistive, they are more transparent. However, the drawbacks are still the possibility of damage to the electrically conductive coating and insensitivity to touch with non-conductive objects, even with gloves on.
- In secured premises
- Information kiosks
- Some ATMs
Projected Capacitive touch screen
Projected capacitive screens are based on measuring the capacitance of a capacitor formed between a person’s body and a transparent electrode on a glass surface, which in this case is an insulator. Due to the fact that the electrodes are applied on the inner surface of the screen, such a screen is extremely resistant to mechanical damage, and taking into account the possibility of using thick glass, projection-capacitive screens can be used in public places and on the street without any special restrictions. In addition, this type of screen recognizes finger-gloved finger presses.
These screens are quite sensitive and distinguish clicks with a finger and a conductive pen, and some models can recognize multiple clicks (multitouch). The projection-capacitive screen features are high transparency, durability, and immunity to most contaminants. The disadvantage of this screen is not very high accuracy, as well as the complexity of the electronics that processes the coordinates of pressing.
- Electronic kiosks on the streets
- Payment terminals
- Laptop touchpads
With the definition of surface acoustic waves
The essence of the touch panel with the determination of surface acoustic waves is the presence of ultrasonic vibrations in the thickness of the screen. When you touch the vibrating glass, the waves are absorbed, while the touchpoint is recorded by the screen sensors. The advantages of the technology can be termed high reliability and pressure recognition (unlike capacitive screens). Cons are weak protection from environmental factors, therefore screens with surface-acoustic waves cannot be used outdoors, and in addition, such screens are afraid of any pollution that blocks their work. They are rarely used.
Other, rarely used types of the touch screen monitor
- Optical screens. Glass is illuminated with infrared light, as a result of touching this glass, the light scatters, which is detected by the sensor.
- Induction screens. Inside the screen, there is a coil and a grid of sensitive wires that respond to touch with an active pen, powered by electromagnetic resonance. It is logical that such screens respond to clicks only with a special pen. Used in expensive graphics tablets.
- Strain-gauge-type – react to screen deformation. Such screens have low accuracy but are very durable.
- The infrared ray grid is one of the very first technologies to detect a touch on the screen. The grid consists of many light emitters and receivers located on the sides of the screen. It reacts to the blocking of the corresponding rays by objects, on the basis of which it determines the coordinates of pressing.
Using an induction screen in a laptop
- A multi-touch that everyone is talking so much about and growing in popularity is not a type of touchscreen. At its core, multi-touch technology – which is a free translation of the multi-touch phrase – is an addition to the touch screen (most often built on the projection-capacitive principle), which allows the screen to recognize several points of contact with it. As a result, the multi-touch screen becomes capable of recognizing gestures. Here are just a few of them:
- Move two fingers together – reduce image (text)
- Spread two fingers apart – zoom
- Flick with multiple fingers at the same time – scroll text, page in browser
- Two-finger rotation on the screen – image (screen) rotation
About the benefits and disadvantages of touch screens
In handheld devices, touch screens have long appeared. There are several reasons for this:
- Ability to make the minimum number of controls
- Graphical interface simplicity
- Ease of control
- The efficiency of access to device functions
- Enhancing Multimedia Features
However, there are more than enough disadvantages:
- Lack of tactile feedback
- Frequent need to use a pen (stylus)
- The possibility of damage to the screen
- Fingerprints and other dirt on the screen
- Higher energy consumption
As a result, it is not always possible to completely get rid of the keyboard, because it is much more convenient to type text using the usual keys. But the touch screen is more interactive, thanks to a faster access to menu items and settings of modern gadgets.
We hope that this material will help you when choosing a device with a touch screen monitor.