Types of Smartphone touchscreen Displays.
Have you ever came across the terms such as CAPACITIVE, RESISTIVE, LCD, TFT-LCD, IPS-LCD, LED, OLED, AMOLED, super-AMOLED, etc. you might have noticed this while buying a new Smartphone, Laptop, Tablet. If you don’t have idea about this terms and you are about to buy your new Smartphone, then you must know all this terms briefly that will help you to make a better choice for your phone.
It’s really a wonder how mobile phones have taken place of typical wired telephone device. Now mobile phones have became the most essential part of our life. We even can’t imagine a day without mobile phones, Nor without a network. So, what has drastically changed in mobile phones is that phones are not merely remained for the purpose to make calls, now their capacity is to handle vital functions, you can play games, watch movies, surf on net, watch T.V. and lots more. On every coming tomorrow your mobile phones will become smarter and smarter.
There are lots of components such as RAM, ROM, CAMERA, PROCESSOR, BATTERY, SCREEN, etc. that play key role in increasing the efficiency of your Smartphone. But in this article we will consider the types of Mobile (Smartphone) screen, this will help you to understand and decide the most suited mobile screen for you. We will go on each type of displays briefly.
Prominently there are two types of touch screen displays –
Capacitive and Resistive which are both based on TFT technology.
Resistive touch screens operate by sensing direct pressure applied by the user. It can be activated by pressing it not only with a finger but also with a stylus A resistive touch screen consists of a touch layer placed on top of a standard display. The touch layer normally includes two transparent electrical layers separated by a small gap.
Pressing the display’s surface causes the two separate layers to come into
contact, which creates an electrical connection that can be sensed and located.
A capacitive touchscreen also consists of two spaced layers of glass, which are coated with conductor such as Indium Tin Oxide (ITO). 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 had touched the screen.
LCD is a flat panel display technology. LCDs are very thin but are actually composed of several layers. Those layers include two polarized panels, with a liquid crystal solution between them. Light is projected through the layer of liquid crystals and is colorized, which produces the visible image. Each pixel has a red, green, and blue sub-pixel. RGB sub-pixel that can be turned on or off. When all of a pixel’s sub-pixels are turned off, it appears black. When all of the sub-pixels are turned on 100%, it appears white. By adjusting the individual levels of red, green, and blue light, millions of color combinations are possible.
LCD has backlight that provides light to individual pixels arranged in a rectangular grid. The liquid crystals do not emit light themselves, so LCDs require a backlight. That means LCD display consumes more power and drains your mobile battery quickly. LCDs are thin and light, though, and generally cheaper to produce.
There are two types of LCD Displays used in a Smartphone
TFT stands for a thin-film-transistor, and is used with LCD to improve image quality. TFT-based displays have a transistor for each pixel on the screen, which offers more control over the images and colors that it renders. All the pixels on a TFT LCD screen are configured in a row and column format, and each pixel is attached to an amorphous silicon transistor that rests directly on the glass panel. This allows the electrical current that illuminates the display to be turned on and off at a faster rate, which makes the display brighter and shows motion smoother. TFT LCDs can deliver sharp images, but they tend to offer relatively poor viewing angles. Which means TFT-LCD’s looks best when it is viewed head on, but it’s poor for side view.
Large TFT displays consume more power and hence are not battery friendly. But since these are cheaper to manufacture these are found on budget phones, feature phones and lower end Smartphone’s.
IPS stands for In-Plane Switching, is a type of high-quality display technology typically deployed in high-performance computer and laptop monitors, tablets and Smartphone’s. Main difference between TFT & IPS is IPS LCD provides a better user experience because of its wider angle and enhanced color quality.
IPS-LCDs feature two transistors for each pixel, whereas TFT-LCDs use just one. This requires a more powerful backlight, which delivers more accurate colors and lets the screen be viewed from a wider angle. The downside of an IPS-LCD is that it consumes more power than a TFT-LCD, possibly up to 15% more. They are also more expensive to make and have longer response times. IPS-LCDs are costlier than normal TFT LCD and hence are found only on higher end Smartphone’s.
LED stands for light-emitting diode, in this type of display technology it uses a panel of LED’s as the light source. An LED display consists of a number of LED panels that, in turn, consist of several LED’s. The biggest advantage of the LED display is its efficient and low-energy consumption, which is especially needed for handhelds and chargeable devices as mobile phones and tablets. Apart from low-power consumption LED displays produce greater light intensity and good image quality.
Types of LED displays used in mobile phones are
OLED stands for Organic LED. Organic Light Emitting Diode (OLED) display technology is much better compared to the LCD display technology because of its excellent color reproduction, faster response times, wider viewing angles, higher brightness and extremely light weight designs. In OLED technology a layer of organic material (carbon based) is sandwiched between two conducting sheets (an anode and a cathode), which in turn are sandwiched between a glass top plate (seal) and a glass bottom plate (substrate). When electric pulse is applied the two conducting sheets, electro-luminescent light is produced directly from the organic material sandwiched between. Brightness and color can vary depending on the electric pulse.
AMOLED stands for active-matrix organic light-emitting diode. It adds a layer of semiconducting film behind the OLED panel which allows it to more quickly activate each pixel. That increased speed makes it ideal for larger, higher definition displays with a lot of pixels. In fact it’s as much as 1000 times faster than LCD. But AMOLED consume significantly less power. This advantage makes active-matrix OLEDs well suited for portable electronics where battery power consumption is critical.
AMOLED screens also tend to have great contrast, as the light on the screen comes from each individual pixel rather than a backlight; when it needs to create a black colour it simply dims or turns off the relevant pixels, for a true, deep black. An AMOLED touch screen usually has an extra, touch sensitive layer on top of the screen
Super AMOLED displays are an even advanced version of AMOLED displays developed by Samsung. Super AMOLED screens are built with capacitive touch sensors on the display itself. This makes it the thinnest display technology on the market.
The result of this is the screen becomes much thinner, lighter, more touch sensitive and less power-hungry, but without that extra layer it’s also far less reflective than a typical AMOLED screen, making it easier to view in bright sunlight. Super AMOLED displays are also much more responsive than other AMOLED displays.