How to choose from the variety of modern smartphones what is right for you? Today the bad-android team has prepared a material with useful advice on the selection of displays.
How not to overpay for a device? How to figure out what to expect from it by the type of display?
Matrix types
Modern smartphones use three basic types of matrices.
The first one, called it, is based on organic LEDs. The other two types are based on liquid crystals - IPS and TN + film.
It is impossible not to mention the frequently encountered abbreviation TFT.
TFT - these are thin-film transistors that control display subpixels (subpixels are responsible for the three primary colors, on the basis of which "full" "multicolor" pixels are formed, which we will talk about a little later).
Technology TFT applied in all three the types of matrices listed above. That is why the common comparison TFT and IPS is absurd in nature.
For many years, amorphous silicon has been the main material for TFT matrices. At the moment, an improved production of TFT matrices has been launched, in which the main material is polycrystalline siliconsignificantly increasing energy efficiency. The size of the transistors has also decreased directly, which allows you to achieve the highest performance ppi (pixel density).
So, we figured out the matrix base, it's time to talk directly about the matrix data types.
TN + film matrix
These matrices were the first to appear in smartphones. At the moment, they remain the most primitive and, accordingly, the cheapest.
Advantages:
Affordable cost
Disadvantages:
Small viewing angles (maximum 60 degrees)
Invert the image even at small tilt angles
Low contrast
Poor color rendering
Most manufacturers have practically abandoned the use of this type of matrix due to too many shortcomings.
IPS matrix
At the moment, this type of matrix is \u200b\u200bthe most common. Also, IPS matrices are sometimes denoted by the abbreviation SFT.
History IPS-matrix dates back to several decades. During this period, many different modifications and improvements were developed. IPS-displays.
When listing the disadvantages and advantages of IPS, it is necessary to take into account the specific subtype... Summarizing, for the list of IPS strengths, we will take the best subtype (respectively, the most expensive), and for the cons we will mean the cheapest subtype.
Advantages:
Excellent viewing angles (maximum 180 degrees)
High-quality color rendering
High ppi display capability
Decent energy efficiency
Disadvantages:
Picture fading when the display is tilted
Over-saturation or, on the contrary, insufficient color saturation
AMOLED matrix
The matrix provides the deepest blacks compared to the other two types of matrix. But it was not always so. The first AMOLED-matrixes had incredible color reproduction and insufficient color depth. The acidity of the picture was present, the brightness was too intense.
Until now, due to internal incorrect settings, some displays are almost identical in perception to IPS. But in super-AMOLED displays, all flaws have been successfully fixed.
With the list of advantages and disadvantages, let's take a conventional AMOLED matrix.
Advantages:
The highest quality picture among all existing types of matrices
Low power consumption
Disadvantages:
Occasionally unequal LED lifetime (different colors)
The need to carefully tune AMOLED display
Let's summarize the intermediate result. It is obvious that the matrix is \u200b\u200bthe leader in image quality. It is AMOLED displays that are installed on the most top-end devices. In second place are IPS matrices, but you should be careful with them: manufacturers rarely indicate the subtype of the matrix, and this is what plays a key role in the final image level. An unambiguous and firm "no" should be said to devices with TN + film matrices.
Subpixels
The determining factor in the final display quality is often hidden display characteristics. Image perception is strongly influenced by subpixels.
In case of LCD the situation is quite simple: each color ( RGB) a pixel consists of three subpixels. The shape of the subpixels depends on the modification of the technology - the subpixel can be in the form of a "check mark" or a rectangle.
In the implementation of displays in terms of subpixels, everything is somewhat more complicated. In this case, the subpixels themselves act as the light source. As you know, the human eye is less sensitive to blue and red, in contrast to green. That is why the repetition of the IPS subpixel pattern would significantly affect the picture quality (naturally, in worst side). To preserve the realism of color reproduction, technology was invented.
The essence of the technology is to use two pairs of pixels: RG (red-green) and BG (blue-green), which, in turn, consist of the corresponding subpixels of the corresponding colors. A combination of subpixel shapes has been applied: the green ones are elongated, while the red and blue ones are almost square.
The technology turned out to be not very successful: the white color was frankly "dirty", and also there were jagged edges at the joints of different shades. With a low rate ppi a grid of subpixels became visible. Such matrices have been installed on a number of smartphones, including flagships. The last flagship that was "lucky" to get the PenTile-matrix was Samsung Galaxy S III.
Naturally, it was impossible to leave the situation with low-quality implementation of subpixels in the same state, so it was soon produced upgrade above the described technology, which received the prefix Diamond.
By increasing the ppi Diamond PenTile allowed to get rid of the problem with jagged borders between colors, and white became much "cleaner" and more pleasing to the eye. And it is this development that is installed in all Samsung flagships, starting with the Galaxy S4.
And here IPS-matrices, although they are generally considered to be weaker than theirs, however, have never encountered such problems.
What conclusion can be drawn? You should definitely pay attention to the amount ppi in case of purchasing a smartphone with a matrix. A high-quality picture is possible only with an indicator from 300 ppi... But with IPS matrices of such strict restrictions are not.
Innovative technologies
Time does not stand still, talented engineers continue to painstakingly work to improve all the characteristics of smartphones, including matrices. One of the latest major developments is the technology OGS.
OGS is an air gap between the screen itself and the projection-capacitive sensor. In this case, the technology met expectations by 100%: the quality of color reproduction, maximum brightness and viewing angles increased.
And over the past few years OGS has become so deeply embedded in smartphones that it is possible not to meet the implementation of the display with a "hamburger" stuffed with an air gap only on the simplest devices.
In their search for display optimization, designers stumbled upon another interesting opportunity to improve the picture on phones. In 2011, experiments began on form glass. Perhaps the most common form of glass among the unusual has become 2.5D - with the help of the curved edges of the glass, the edges become smoother, and the screen is voluminous.
Company Htc released a smartphone Sensation, the glass of which has been concave in the center of the display. According to HTC engineers, this increases the scratch and shock resistance. But glass concave to the center has not received widespread use.
The concept of bending the display itself has become more popular, and not just glass, as it was done in. One of the side faces of the display got a curved shape.
A very interesting characteristic to look out for when buying a smartphone is sensor sensitivity... Some smartphones are equipped with a sensor with increased sensitivity, which allows you to fully use the display even with ordinary gloves. Also, some devices are equipped with an inductive substrate to support the stylus.
So for those who like to write in the cold or use a stylus, the sensitive sensor will definitely come in handy.
Known Truths
It's no secret that screen resolution also has a big impact on the final image level. Without further comment, we bring to your attention a table of correspondence between display diagonal and resolution.
Conclusion
Each matrix has its own characteristics and hidden characteristics. You should be careful with -disks, or rather, with the ppi pixel density: if the value less than 300 ppi, then the quality of the picture you frankly will disappoint.
For IPS-matrix is \u200b\u200bimportant subtype, and depending on the subtype, the cost of a smartphone is logically proportionally increased.
Curved glass 2.5D will greatly increase the attractiveness of the picture, like the technology OGS.
The issue of display size is purely individual, but with multi-inch "shovels" a high resolution will be appropriate.
We wish you pleasant shopping, friends!
Stay tuned, more to come a lot of interesting.
Articles and Life Hacks
Smartphone screens sometimes use a technology called Full Lamination, or full lamination. focus on the "progressiveness" of such displays in comparison with "ordinary" ones.
At the same time, it is far from immediately possible to understand why they are better. We will try to clarify this issue.
What is it all about
Liquid crystal (LCD) screen matrices appeared a long time ago, and since then have been continuously improved.This is especially true for those used in mobile devices, because in comparison with TVs and monitors, a number of additional requirements are imposed on them.
Touchscreens, in comparison with conventional ones, contain one or more additional layers that allow them to respond to touch.
And it is with regard to their configuration that the battle is unfolding for every fraction of a millimeter of thickness.
GFF
The full name of the technology in question sounds like GFF (Glass-to-film-to-film) full lamination.
A few years ago, GG (glass-to-glass) displays were common, in which two layers of glass were used, separated from the sensor layer and the TFT matrix itself by an air gap.
They had a number of disadvantages: relatively large thickness, low manufacturability and rather high cost.
They were replaced by GFF matrices, in which one of the glass layers was replaced by two polymer films separating the indium tin oxide (ITO) sensor layers from the TFT matrix and cover glass. This technology was also known as On-Cell.
The result was a decrease in the thickness of the sensor layer from 0.65-1.25 mm for GG matrices to 0.25-0.5 mm for screens made using GFF Full lamination technology. At the same time, the cost of manufacturing has decreased, which is reflected in the price of the final product - the gadgets themselves.
In-Cell
No matter how advanced the technology is, over time, something more perfect will inevitably appear. At the end of 2012, the first gadget appeared on the market using a new one - Apple iPhone 5.In this case, the "sandwich" of layers has become even thinner: the touch layer was integrated directly into the surface of the TFT matrix, which made it possible to achieve an even greater gain in display thickness.
Large vendors specializing in the production of screens for mobile devices quickly picked up the novelty, and the company LG Displays, which uses, among other things, presented its version of the technology called AIT.
Most likely, this was due to some subtleties related to intellectual property.
OGS
Sometimes in sources in connection with Full lamination, the name OGS is found, which is an abbreviation for One Glass Solution.
Finally
Today, GFF Full lamination technology can be considered obsolete. It finally gave way to the more progressive In-Cell, and displays with its use are no longer produced.It is also worth noting that all of the above refers exclusively to the touchscreen layer, without affecting the parameters of the IPS matrix itself.
Therefore, this technology has nothing to do with the resolution, brightness or clarity of the image, no matter what the advertising brochures are grinding. The characteristics that really relate to it are the thickness of the display and the response time.
Smartphone display technologies do not stand still, they are constantly being improved. Today there are 3 main types of matrices: TN, IPS, AMOLED. Often there are disputes over the advantages and disadvantages of IPS and AMOLED matrices, their comparison. But TN screens have long been out of fashion. This is an old development that is practically not used in new phones now. Well, if it is used, then only in very cheap state employees.
Comparison of TN matrix and IPS
TN matrices appeared in smartphones first, so they are the most primitive. The main advantage of this technology is its low cost. The cost price of a TN display is 50% lower than that of other technologies. Such matrices have a number of disadvantages: small viewing angles (no more than 60 degrees. If more, the picture begins to distort), poor color rendering, low contrast. The logic of manufacturers to abandon this technology is clear - there are a lot of shortcomings, and they are all serious. However, there is one benefit: response time. In TN matrices, the response time is only 1 ms, although in IPS screens, the response time is usually 5-8 ms. But this is just one plus that cannot be put in opposition to all the minuses. After all, even 5-8 ms is enough to display dynamic scenes and in 95% of cases the user will not notice the difference between the response time of 1 and 5 ms. In the photo below, the difference is clearly visible. Pay attention to the color distortion at an angle on the TN matrix.
Unlike TN, IPS matrices show high contrast and are distinguished by huge viewing angles (sometimes even maximum). This type is the most common and is sometimes referred to as SFT matrices. There are many modifications of these matrices, so when listing the pros and cons, you need to keep in mind a specific type. Therefore, below, to list the advantages, we will mean the most modern and expensive IPS-matrix, and to list the disadvantages, the cheapest.
Pros:
- Maximum viewing angles.
- High energy efficiency (low energy consumption).
- Accurate color reproduction and high brightness.
- Ability to use high resolution, which will give higher pixel density per inch (dpi).
- Good sun behavior.
Minuses:
- Higher price compared to TN.
- Distortion of colors with a large tilt of the display (however, viewing angles are not always maximum on some types).
- Over-saturation and under-saturation.
Most phones today have IPS panels. Gadgets with TN displays are used only in the corporate sector. If a company wants to save money, it can order monitors or, for example, phones for its employees at a lower price. They may contain TN-matrices, but no one buys such devices for themselves.
Amoled and SuperAmoled screens
Most often, Samsung smartphones use SuperAMOLED matrices. It is this company that owns this technology, and many other developers are trying to buy or borrow it.
The main feature of AMOLED matrices is the depth of black. If you put an AMOLED display and IPS next to it, then the black color on the IPS will appear light compared to AMOLED. The very first such matrices had incredible color reproduction and could not boast of color depth. Often the so-called acidity or excessive brightness was present on the screen.
But the developers at Samsung have fixed these shortcomings in SuperAMOLED screens. These have specific advantages:
- Low power consumption;
- The best picture compared to the same IPS matrices.
Disadvantages:
- Higher cost;
- The need to calibrate (adjust) the display;
- Rarely can there be a different diode life.
The most TOP flagships are equipped with AMOLED and SuperAMOLED matrices due to the best picture quality. The second place is occupied by IPS screens, although it is often impossible to distinguish between AMOLED and IPS matrix by the picture quality. But in this case it is important to compare subtypes, not technologies in general. Therefore, you need to be on the alert when choosing a phone: often advertising posters indicate technology, and not a specific subtype of the matrix, and technology does not play a key role in the final image quality on the display. BUT! If TN + film technology is indicated, then in this case it is worth saying “no” to such a phone.
Innovation
Removal of air gap OGS
Engineers present image enhancement technologies every year. Some of them are forgotten and not applied, and some make a splash. OGS technology is just that.
By default, the phone screen consists of a protective glass, the matrix itself and an air gap between them. OGS allows you to get rid of the extra layer - the air gap - and make the matrix part of the protective glass. As a result, the image appears to be on the surface of the glass, and not hidden under it. The effect of improving the display quality is obvious. Over the past couple of years, OGS technology has been unofficially considered the standard for any more or less normal phones. Not only expensive flagships are equipped with OGS screens, but also state employees and even some very cheap models.
Screen glass bending
The next interesting experiment, which later became an innovation, is 2.5D glass (that is, almost 3D). The folds around the edges of the screen make the picture appear more voluminous. If you remember, the first smartphone Samsung Galaxy Edge made a splash - it was the first (or not?) To get a display with 2.5D glass, and it looked amazing. An additional touch panel has even appeared on the side for quick access to some programs.
HTC tried to do something different. The company has created the Sensation smartphone with an inwardly curved display. Thus, it was protected from scratches, although it was not possible to achieve greater benefit. Nowadays, such screens cannot be found due to the already durable and scratch-resistant Gorilla Glass protective glass.
HTC didn't stop there. The LG G Flex smartphone was created, which not only had a curved screen, but also the body itself. This was the "trick" of the device, which also did not gain popularity.
Stretchable or flexible screen from Samsung
As of mid-2017, this technology is not yet used in any phone on the market. However, Samsung is showing AMOLED screens in videos and presentations that can stretch and then return to its original position.
Photo of flexible display fromSamsung:
The company also presented a demo video, where the screen is clearly visible, arched by 12 mm (as the company itself claims).
It is possible that soon Samsung will make a very unusual revolutionary screen that will amaze the whole world. This will revolutionize display design. It's hard to imagine how far the company will go ahead with this technology. However, it is possible that other manufacturers (Apple, for example) are also developing flexible displays, but so far there have been no such demonstrations from them.
The best smartphones with AMOLED matrices
Considering that SuperAMOLED technology was developed by Samsung, it is mainly used in models from this manufacturer. In general, Samsung is leading the way in developing improved screens for mobile phones and televisions. We have already understood this.
By far the best display of any smartphone in existence is the SuperAMOLED screen in the Samsung S8. This is even confirmed in the DisplayMate report. For those not in the know, Display Mate is a popular resource that analyzes "inside and out" screens. Many experts use their test results in their work.
To define the screen in S8, I even had to introduce a new term - Infinity Display... It got this name due to its unusual elongated shape. Unlike its previous screens, Infinity Display has been seriously improved.
Here's a short list of the benefits:
- Brightness up to 1000 nits. Even in the bright sun, the content will be well readable.
- A separate chip for the Always On Display technology. The already economical battery now consumes even less battery power.
- Picture enhancement function. In Infinity Display, content without an HDR component acquires it.
- Brightness and color settings are automatically adjusted based on user preference.
- Now there are not one, but two light sensors, which more accurately allows you to automatically adjust the brightness.
Even when compared to the Galaxy S7 Edge, which had a “reference” screen, the S8's display looks better (whites are really white on it, and warm colors on the S7 Edge).
But besides the Galaxy S8, there are other smartphones with screens based on SuperAMOLED technology. Basically, these are, of course, the models of the Korean company Samsung. But there are others as well:
- Meizu Pro 6;
- OnePlus 3T;
- ASUS ZenFone 3 Zoom ZE553KL - 3rd place in the TOP of Asusu phones (located).
- Alcatel IDOL 4S 6070K;
- Motorola Moto Z Play, etc.
But it is worth noting that the hardware (that is, the display itself), although it plays a key role, is also important, the software, as well as minor software technologies that improve the picture quality. SuperAMOLED displays are famous primarily for the ability to widely adjust the temperature and color settings, and if there are no such settings, then the point of using these matrices slightly disappears.
Glass Solution (OGS) technology enables the creation of low-cost projected capacitive touchscreen displays. How it works?
There are several reasons why capacitive touchscreens are much more expensive than resistive ones. One of the reasons is the large bonding surface of the protective glass with the touch sensor. If an error occurs during gluing, both the protective glass and the expensive sensor are sent for recycling. Densitron is one of the few that supplies displays and sensors that can be separated in the event of a mistake during the bonding phase. This significantly reduces the number of defective products.
All components on one glass substrate
With the advent of OGS technology, capacitive touch panels have reached the same cost level as resistive ones. Instead of gluing multiple layers - a sensor substrate and a protective glass film - OGS allows all components to be combined on a single glass substrate. Thus, the production cost is greatly reduced. OGS-displays, at the request of the client, can take various configurations, the required rigidity and strength, depending on the thickness of the glass substrate.
Apart from the simplicity of the mechanical structure, OGS panels have another advantage: they are very thin. The standard glass thicknesses are 1.2 mm and 1.8 mm. If you need a particularly durable display - for example, for ATMs - glass is produced with a thickness of 3.4 mm. It is possible to manufacture miniature displays with a thickness of less than 1.2 mm - for example, for smart watches. The dimensions of the OGS screen can be up to 480 mm x 340 mm. Therefore, the screen size can range from less than 1.44 "" (3.66 cm) to 15.6 "" (39.94 cm).
Freedom of choice of shape
As with conventional Projection Capacitive Sensors (P-CAPs), the sensor area can only cover the display area, but it can cover other working surfaces as well. OGS technology allows you to punch holes or rounds right in the screen. It is also possible to carry out chemical surface hardening and any other processing of protective glass, including polychrome printing on it. OG S technology can be used to create PM and AMOLED displays.
The wide range of possibilities for creating various forms suggests application in a wide variety of industries. The OGS screen can take on almost any flat shape. If the protective glass reaches the very border of the product, then after appropriate grinding and polishing it will serve as a stylish element for decorating the product. In addition, glass has undoubted advantages: high hardness (up to 9H) and high strength. A successful test was carried out in which a steel ball fell from a height of 1 m onto 1.1 mm glass.
The protective glass makes the display and sensor resistant to water and dust. Complete tightness determines compliance with the IP65 moisture and dust protection class. After connecting the display / sensor contacts, the protective glass is glued to the back of the case. 3M Adhesive Tape can even be pre-glued one side to the case so that when assembly is complete, you can simply peel off the protective film and adhere the touchscreen.
Indium oxide (ITO) conductors with a thickness of only 5 μm make the sensor very thin. The OGS display consists of various layers: ITO electrodes, through-connections, insulation layers and silver layers. The process must be constantly monitored because the structure of the display consists of very delicate and complex structures. At the Densitron plant in Shenzhen, specialists achieve the highest precision: the product yield is almost 100%.
10-finger multisensor
The connections between the individual electrodes located in parallel and perpendicular to each other are made using silver plating, so they can also contact through carbon inclusions. When designing OGS glass, it is necessary to provide sufficient space for the conductors. Conventional CCDs offer less lead space on the surface of the sensing zone because the leads are run on two independent layers, which makes them easier to wire.
Conventional CCD controllers mount with the sensor on a flat cable and are suitable for Android, Microsoft and Linux. The display copes with a large number of simultaneous touches (up to 10). I 2 C or USB connectors are provided. Taking into account the number of controller channels (from 30 to 68), maintenance of displays based on projection-capacitive technology should be carried out not only with thin rubber gloves, but also with thick woolen gloves (the presence of water or dirt is not taken into account). With software it is possible to set parameters such as sensitivity, sudden brightness change (random command set) and minimum finger size. As a result, serviceability is maintained both under normal conditions and when the display is in a hostile environment.
Benefits of containment design
OGS-based screens are the ideal solution when you need to create custom designs. There are also thin-film and projected capacitive modules with the usual design of protective glass, the edges of which are pressed against a black frame, and the size and shape depend on the display format. The OGS module is easy to integrate into a device with a display of any shape. This is a great opportunity to save money, considering the cost of any custom designs. Alternatively, you can use a standard display first, which will also reduce the initial cost of the instrument.
Projected Capacitive Technologies and especially OGS are ideal for use in medicine, since there is no need to use aggressive detergents that can get inside the device due to the absence of dirty frames on the front surfaces of screens. OGS screens are also ideal for mobile devices: since the protective glass and sensor are no more than 1.2 thick, the device will be thin and light.
Recently, in the technical characteristics of the selected smartphone, you can see the inscription "OGS". Today this technology is quite promising and therefore is widely used by many manufacturers. So what is an OGS display and what does this cryptic acronym mean to users?
As you know, the screen module of a modern smartphone consists of two parts: a matrix, which forms a picture from pixels, and a touchscreen, an element that protects the display from damage and reacts to finger touches.
OGS (One Glass Solution - from English "solution with one glass") - a technology that allows you to place a layer of touch glass not above the screen, but to make it an integral part. Thus, the thickness of the device is reduced and some consumer qualities of the display are improved (about (see this just below).
There are two types of OGS technology: "sensor on the lens" (where "lens" is a layer of protective glass) and "sensor in a cell". In the first case, the protective glass of the LCD panel also serves as a sensor; a layer of a sensitive coating is applied on its inner side, which is located in the immediate vicinity of crystals or diodes (in OLED displays). “Sensor in a cell” is a type of OGS technology, when using a sensitive element covers a thin glass of the matrix from the outside, and another protective layer is applied to it (often “Gorilla Glass” or “Dragontail”).
Pros and cons of displays withOGS
This technology certainly has a number of advantages:
- small thickness;
- optimized energy consumption;
- good color rendering indicators;
- low refractive index, as a result, good viewing angles;
- high degree of transparency;
- protection against pollution (dust formation between the display and the touchscreen is excluded: there is simply no place for it).
Nothing is perfect, and OGS technology is proof of this. Developers have a lot to develop, because it also has disadvantages:
conclusions
Thus, OGS is a display construction technology in which the entire touch panel structure consists of one module. This solution allows you to reduce the thickness of the smartphone, reduce its power consumption, and improve the quality of the picture on the screen.
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