The article has been divided into two parts because of its greater length. Its the part number 1 of the review. here we have discussed about Types of matrices of The screens in smartphones: which to choose?
You can find the discussion about the other ideas about The screens in smartphones in part 2 of the article.
Before the mass distribution of smartphones, with the purchase, we evaluated their phones mainly in design and only occasionally paying attention to functionality. Times have changed: now all smartphones have similar capabilities, but when you look only at the front panel, one gadget can barely be distinguished from the other. We came to the fore the technical characteristics of the devices, and the most important among them is the screen for many. We will explain what lies behind the terms TFT, TN, IPS, PLS, and help you choose a smartphone with the desired characteristics of the screen.
Types of matrices
In today's smartphones are mostly used three matrices production technology: two are based on liquid crystals - TN + film and IPS, and the third - AMOLED - OLED. But before you start, it is necessary to talk about the TFT abbreviation, which is the source of many errors. TFT (thin-film transistor) - thin-film transistors is used to control the operation of each subpixel modern screens. TFT technology is used in all the above-mentioned types of screens, including the AMOLED, so if somewhere says about the comparison TFT and IPS, it is at the root of the question is incorrect.
Most TFT-matrix amorphous silicon is used, but recently have been introduced into production on the TFT polycrystalline silicon (LTPS-TFT). The main advantages of the new technology - reduction of energy consumption and the size of transistors that can achieve high values of pixel density (500 ppi). One of the first smartphones with IPS-matrix display and LTPS-TFT became OnePlus One.
Now that we have dealt with the TFT, proceed directly to the matrix type. Despite the wide variety of LCD varieties, they all have the same basic principle of work: applied to the liquid crystal molecules sets the current angle of light polarization (it affects the brightness of the sub-pixel). The polarized light then passes through a filter and is colored in the color of the corresponding sub-pixel. The first smartphones appeared in the most simple and cheap matrix TN + film, whose name is often abbreviated to TN. They have small viewing angles (up to 60 degrees at a deviation from the vertical), with even at small slopes image on such screens inverted matrices. Among other shortcomings of TN-matrices - low contrast and low color accuracy. To date, such screens are used only in the most cheap smartphones, and the vast majority of new gadgets are already more advanced displays.
The most common mobile gadgets is now the IPS technology, sometimes referred to as SFT. IPS-matrix appeared 20 years ago and has since been released in different versions, of which close to two dozen. However, the highlight among them is the ones that are the most technologically advanced and widely used at the moment: AH-IPS of LG's and PLS - from Samsung, which are very similar in their properties, even a cause for litigation between manufacturers . Modern versions have an IPS wide viewing angles that are close to 180 degrees, realistic color reproduction and provide the ability to create displays with high pixel density. Unfortunately, gadgets manufacturers almost never tell the exact type of IPS-matrix, even when using a smartphone differences will be visible to the naked eye. For cheaper IPS-matrix is characterized by discoloration of the images when the screen is tilted, and low color accuracy: the image can be either too "acid" or, on the contrary, "washed-out".
With regard to energy, the liquid crystal displays is largely determined by the power of illumination elements (in smartphones used for this purpose LEDs), so the consumption of matrix TN + film and IPS can be regarded as about the same coinciding with the level of brightness.
The LCD quite similar matrices that are based on organic light emitting diodes (OLED). They serve as the light source itself subpixels representing subminiature OLEDs. Since there is no need for external lighting, such screens can be made thinner LCD. The smartphone uses a variety of OLED technology - AMOLED, which uses an active TFT-matrix to control the sub-pixel. It allows color AMOLED display, while the conventional OLED panel can only be monochrome. AMOLED-matrix provide the deepest black color, because its "display" only required to completely disable the LEDs. Compared to LCD, these matrices have a lower power consumption especially when using dark skins, in which black portions of the screen does not consume energy. Another characteristic feature of AMOLED - too saturated colors. In the early days of its appearance matrices were really improbable color rendering, and, although such "children's sores" is long gone, still the majority of smart phones with such screens have built-saturation setting, which allows you to bring the image on the AMOLED according to the perception of the IPS-screens.
Another limitation of AMOLED screens used was uneven service life of LEDs of different colors. After a couple of years of use of the smartphone it could lead to burnout sub-pixels and a residual image of some elements of the interface in the first place - in the notification bar. But, as in the case of the color reproduction, this problem has long receded into the past, and modern organic LEDs are designed for at least three years of continuous work.
To sum up the brief. The most vivid image quality and at the moment bespechivaet AMOLED-matrix: even Apple's, according to rumors , in one of the next iPhone will use such displays. But it is necessary to consider that all the latest developments the Samsung company, as the main producer of such panels, leaving myself and the other producers selling "last year's" matrix. Therefore, when choosing a smartphone from Samsung is not looking in the direction of high-quality IPS-screen. But gadgets with displays TN + film chosen in any case not worth it - today this technology is already considered obsolete.
click here to read part 2 of the review
