#activematrixorganiclight-emittingdiode

Of course, the South Korean giant is one of the leaders in the segment of high-tech consumer electronics. At the end of the last century, the company focused its efforts on the development of high technologies, using innovation as the main tool for successful competition. As a result, the company almost every year offers innovative models in almost all segments of consumer electronics. Today Samsung smartphones, TVs, robotic vacuum cleaners, refrigerators, etc convincingly prove the correctness this strategic decision. Of course, Samsung’s own developments radically expand the capabilities of South Korean engineers with high-tech innovative components. Today Samsung develops and manufactures high-performance Exynos processors, fast UFS (Universal Flash Storage) smartphone storage, excellent high-contrast AMOLED (Active Matrix Organic Light-Emitting Diode) matrices, convenient One UI software overlay. After the acquisition of Harman Kardon and AKG companies, high-quality acoustics also added to this list.

Samsung One UI software overlay

As known, software overlay is a unique Android version from each manufacturer. Usually, Google develops a new version of the OS, downloads its source code for free, and releases an update for its Pixel smartphones. After that, each manufacturer can take a new free Android version from Google and use it on their smartphone, including after editing. But some companies, including Samsung, are developing their own software overlay. In particular, the first TouchWiz version was introduced on the Samsung F480 Tocco in 2008. At the end of 2016, the company replaced it with Samsung Experience. From January 2017 to August 2018, the company released five versions, including Samsung Experience 8.0 (Android 7.0 Nougat), 8.5 (Android 7.1.1 Nougat), 9.0 (Android 8.0.0 Oreo) and 9.5 (Android 8.1.0 Oreo). At the Samsung Developer Conference 2018, the company introduced the new One UI for the Galaxy series. This new interface for Android 9 Pie is adapted for smartphones with a large display diagonal. In recent years, increasing the screen diagonal is one of the main trends. But this complicates one-handed operation. One UI partially solved this problem by shifting the interface elements to the bottom of the display, which is more accessible to the fingers.

One UI 2

But in October 2019, Samsung released the public beta of One UI 2 version. The list of its main differences includes: - Android 10; - new control gestures have become similar to the iPhone: swipe up - main screen, with a delay - list of apps, side-swipe - return; - compact sizes of various pop-ups. Now the incoming call window takes up much less screen space without closing the app.

- the text color automatically changes depending on the selected wallpaper.

- new design of some sections; - updated report on battery consumption; - new effects of side lighting; - improved camera interface with an expanded selection of modes; - wallpaper section in the screen settings and dimming option; - basket of contacts. But today, One UI 2 is only available in the United States and South Korea.

Chipset

Today, Samsung uses its own Exynos processors and Snapdragon Qualcomm from the American Qualcomm Technologies Inc. In addition, the company does not exclude the possibility of using inexpensive MediaTek chipsets with 5G support for some models of the Galaxy A and M series. The company recently announced the new 5G Exynos Modem 5123 and hyper-fast 7nm Exynos 990 with three-cluster architecture, including dual-core custom CPU, dual-core Cortex-A76 and energy-efficient quad-core Cortex-A55.

According to the company, it provides 20% improved performance. Apparently, it will be used in the next flagship Samsung Galaxy S11 and Note 11, in parallel with modifications based on the Snapdragon 865 processor for the US and Hong Kong markets. As known, the company traditionally uses Snapdragon in models for the US market. Of course, each of the chipsets has pros and cons. Exynos heats up less and consumes less energy, supports 2 SIM cards, uses a more efficient apps manager and receives updates more often. Snapdragon provides higher signal reception quality and better performance, which is especially evident in games.

Smartphone Storage

Previously, almost all mobile phones used eMMC (flash memory plus controller) architecture. The latest eMMC 5.1 version of 2015 provides a reading speed of 250 MB/s and writing - 125 MB/s. In 2016, Samsung first introduced UFS (Universal Flash Storage) memory based on the new operation principle that provides significantly faster read / write speeds. In particular, eMMC uses sequential organization of read / write processes (Half Duplex), while UFS implements them simultaneously (Full Duplex).

As a result, UFS is significantly faster and consumes less power. To date, three UFS versions have been released: - in 2011 - UFS 1.0 - bandwidth up to 300 MB / s; - 2013 - UFS 2.0 - bandwidth up to 1200 MB / s; - 2018 - UFS 3.0 - bandwidth up to 2900 MB / s. The UFS 2.0 / 2.1 and UFS 3.0 support two-band mode (2-lane or dual lane), which doubles the maximum bit rate due to the use четырех каналов (2 write + 2 read). As a consequence, testing UFS 2.1 vs eMMC 5.1 demonstrated 150/750 MB / s (write / read) and 100/280 MB / s, respectively.

AMOLED display

As known, in 2010 Samsung first introduced the Galaxy S smartphone with Super AMOLED (Active Matrix Organic Light-Emitting Diode) display.

Unfortunately, its image quality was significantly inferior to the IPS matrices that Samsung successfully produced for other companies, including Apple. At the same time, the company continued to use PLS (Plane-to-Line Switching) matrices in its own smartphones. But since 2010, Samsung has focused on this new technology. Today, the South Korean giant dominates the mobile OLED display segment. Over the years, the company has expanded the range of AMOLED versions, while eliminating their characteristic problems. For example, PenTile, Pixel Shifting and parallax backgrounds have virtually eliminated the problem of blue pixel burnout. Today, the company uses Super AMOLED, Super AMOLED Plus, HD Super AMOLED and Dynamic AMOLED. Super AMOLED and HD Super AMOLED differ only in the number of sub-pixels and, accordingly, size.

Dynamic AMOLED is Super AMOLED with HDR10 support. Today, Samsung phones use both types of matrices, for example, in the Samsung Galaxy A series of 2019.

Conclusion

A modern smartphone uses a large number of complex components, including main camera and several additional cameras in multi-camera smartphones, chipset, RAM and ROM, operation system, etc. Their specs directly affect the functionality and, as a result, the choice of the optimal model. But of course, the display is one of the main components. Its specs, service life and safety for vision depend on the matrix type. All modern TVs and smartphones use AMOLED (Active Matrix Organic Light-Emitting Diode) or LCD screens. As known, before the invention of OLED technology, LED LCD displays dominated the market. The first light-emitting p-phenylene vinylene (or PPV, or polyphenylene vinylene) polymer was synthesized in the Cavendish Laboratory of the University of Cambridge in 1989. Already in 1992, Cambridge Display Technolodgy (CDT) was established to produce polymer light-emitting materials. But the fierce competition between them began only in the 21st century, provoking their rapid development.

LCD

As known, LCD (Liquid Crystal Display) technology uses fluidity and anisotropy of crystals. In fact, they perform the function of a light filter, forming a pixel of the desired color on the screen surface. Of course, this technology requires a backlight that uses LEDs. In February 2011, Samsung introduced the first QLED display with improved LED backlighting on quantum dots. In fact, engineers added an LED panel instead of traditional cold cathode fluorescent tubes. This technology has significantly expanded the color gamut of the matrix. Further, other companies developed their own technologies based on this idea. Today they use their own marketing names, including NanoCell from LG, Triluminos from Sony and ULED from Hisense. In parallel, companies developed backlight technology. As a result, FALD (full-array local dimming) backlighting was developed. Today, experts expect LCD with innovative miniLED-based backlighting. Unlike traditional backlighting, the size of its diode modules does not exceed 100 microns. The reduction in size promises to drastically reduce energy consumption, increase contrast and color accuracy by increasing the number of local dimming zones. TVs already use this technology. For example, TCL announced 8-series MiniLED Roku TV with 1,000 local dimming zones. In comparison, today the best expensive LCD TVs use no more than a few hundred. This technology promises to bring the quality of LCD screens closer to AMOLED. Some experts were expecting these smartphones in 2019. Unfortunately, their hopes did not materialize.

OLED

OLED matrices (Organic light-emitting diode) use multilayer organic polymers that emit light under the influence of electricity and do not require backlighting. In fact, it's the main difference between these technologies. All modern phones use only AMOLED (Active Matrix OLED) matrices with Active Matrix. But in the TV segment, companies continue to use the acronym OLED without adding AM. In the summer of 2009, LG announced the first 15-inch OLED TV. A few years later, at CES 2012, Samsung and LG introduced 55-inch OLED TVs. At IFA 2013, LG has already announced the world's first 77-inch 4K OLED TV. At CES 2013, Samsung announced the Galaxy S4 with 5 "Super AMOLED Full HD panel. In the second half of 2014, Samsung Display began production of AMOLED flexible panels. Modern models already use AMOLED, Super AMOLED, HD Super AMOLED, Dynamic AMOLED and P-OLED matrices.

MicroLED (mLED or μLED or ILED)

MicroLED is the next step in the development of OLED technology. Like OLED, MicroLED uses subpixel LEDs with its own radiation and does not require backlighting. But as a light-emitting material, OLED uses sm-OLED (Small Molecule-Organic LED), POLED, or PHOLED (phosphorescent OLED). MicroLED uses inorganic GaN (gallium nitride) with a size of only 5-10 microns, which is its main advantage. The new technology has great prospects. In particular, high light output can drastically reduce energy consumption to about 10% LCD and 50% OLED displays, and the miniature size will allow companies to achieve pixel densities of up to 1,500 PPI, providing huge resolution even for large matrices. In 2018, Apple announced plans to produce MicroLED panels. But in 2019, serial microLED displays did not appear on the market. However, Sony and Samsung are already selling microLED The Wall.

OLED advantages

1. As known, contrast characterizes the ratio brightest white to the darkest black pixels on the screen and is measured in the ratio of "maximum brightness" / 1. Thus, a screen with a contrast ratio of 1000: 1 displays white 1000 times brighter than black. But in the OLED display, black color corresponds to a completely off diode with a brightness of "0". Therefore, companies often use the term "Infinite contrast", although, as you know, mathematics prohibits the division by "0". Sometimes companies indicate 2,000,000: 1 and above, which is probably more correct. Unfortunately, LED backlight in the LCD screen fundamentally eliminates the perfect black. 2. Smartphones with OLED screens support Always On-Display mode. In this case, the smartphone’s display can display information by controlling individual pixels. This mode provides a significant reduction in energy consumption when choosing interface in dark colors. But black color of the IPS matrix corresponds to the on backlight, which we do not see due to the light wave damping by the second polarizer. Thus, the IPS matrix cannot provide this useful option because its backlight constantly illuminates the matrix. 3. As known, the image brightness decreases when viewed at an angle. For example, the brightness drop in smartphones with IPS-screen reaches 55% for an angle of 30 degrees. For comparison, brightness reduction of the OLED screen at the same angle does not exceed 25%. 4. The absence of a backlight in OLED screen eliminates problems with its uniformity. Unfortunately, it's relevant for the IPS screen. Typically, companies place backlight diodes along the bottom edge of the IPS screen. During operation, their light passes through a special flexible diffuser made of a thin film. Unfortunately, many LCD screens display a brighter bar at the bottom of the screen near the diodes.

LCD advantages

1. IPS-screen is much cheaper than OLED-analogue, including repair. 2. Almost all OLED screens have problems with Screen burn-in. The service life of green diodes reaches 130,000 hours, red - 50,000 hours, blue - only 15,000 hours. However, today companies successfully solve this problem using PenTile. For example, PenTile technology allowed Samsung to use half as many blue and red subpixels compared to green. Moreover, the most powerful blue diodes operate at half power, saving a resource. It increases their service life, and all subpixels burn out evenly. Typically, companies use RGBG (additional green sub-pixel) or RGBW (additional white sub-pixel). Today AMOLED, Super AMOLED and HD Super AMOLED often use this configuration. On the other hand, 15,000 hours of service life for blue diodes corresponds to more than 5 years of operation, even with heavy use. Most people change models more often. In addition, static displaying for a long time at maximum brightness may form a residual image on the screen. But Pixel Shifting and Parallax Backgrounds successfully solve this problem. Pixel Shifting software algorithm shifts the image by 1 pixel for a prolonged static image. Recently, Google and Apple often use parallax backgrounds, preventing a static image on the screen. 3. Screen flicker due to PWM in OLED screen increases eye strain. As known, the diode brightness depends on the current strength. With its increase, it gradually rises. Unfortunately, the decrease in brightness does not occur smoothly. Instead of smooth dimming, the diodes begin to work with small pauses. For example, diodes burn 0.9 ms for 1 second at 100% brightness. But at 50% brightness, these LEDs only work for 0.45 ms for 1 second. Of course, this flicker significantly increases the load on the eyesight, causing discomfort in the eyes.

Brands

Today, budget and mid-budget Android, and Apple, mainly use LCD displays. This list includes: - iPhone 11; - iPhone XR; - Honor 20/20 Pro; - iPhone 8/8 Plus, iPhone 7/7 Plus; - Xiaomi Redmi Note 7; - Huawei P30 Lite. AMOLED screens are used on almost all flagships and even on mid-range smartphones. This list includes: - the entire line of Samsung Galaxy S-series, Note-series, etc; - iPhone 11 Pro / 11 Pro Max, iPhone XS / XS Max and iPhone X; - Huawei flagships (P30, Mate 30); - Xiaomi flagships (the entire line of Mi 9, etc.); - Sony Xperia XZ3 and Xperia 1.

Conclusion

Of course, a modern smartphone is one of the most complex electronic devices that uses a large number of complex components. Their technical characteristics directly affect the functionality and, as a result, the choice of the optimal model. This list includes the number and set of cameras in multi-camera smartphones and specs on main camera, smartphone performance and smartphone storage, operation system, etc. Of course, the display is one of the main components. But its specs, service life and safety for vision depend on the matrix type. All modern TVs and smartphones use AMOLED (Active Matrix Organic Light-Emitting Diode) or LCD screens. As known, the first light-emitting p-phenylene vinylene (or PPV, or polyphenylene vinylene) polymer was synthesized in the Cavendish Laboratory of the University of Cambridge in 1989. Already in 1992, Cambridge Display Technolodgy (CDT) was established to produce polymer light-emitting materials. In 2004, Samsung introduced the first X120 phone with an OLED screen.

In August 2008, Nokia introduced the N85 with an AMOLED display.

As known, OLED matrices (Organic light-emitting diode) use multilayer organic polymers that emit light under the influence of an electric current. Accordingly, they do not require backlighting. This factor is their main difference from traditional LCD technology. Today, all companies use OLED matrices with Active Matrix only and are called AMOLED (Active Matrix Organic light-emitting diode). In the TVs segment, companies continue to use OLED abbreviation without adding AM.

Pros & Cons

Pros - perfect black due to lack of backlight provides almost endless contrast (2,000,000: 1 and above); - large viewing angles eliminate color distortion even when viewing at an angle; - PWM (pulse-width modulation) provides a wide range of brightness and very accurate color reproduction; - smaller dimensions and weight; - instant response due to lack of inertia; - the ability to create flexible screens; - wide range of operating temperatures from −40 to +70°C. Cons - high price; - screen flicker due to PWM increases eye strain; - low maximum brightness; - high sensitivity to moisture; - slight purple hue due to the eye’s reaction to the blue subpixels. - the limited service life of the blue phosphor due to its chemical characteristics violates the color balance after several years. The service life of green diodes reaches 130,000 hours, red - 50,000 hours, blue - only 15,000 hours. Of course, this problem significantly reduces the competitiveness of AMOLED vs LCD.

PenTile, Pixel Shifting and parallax backgrounds

Today, companies use several basic ways to solve this problem. PenTile (penta + tile) technology integrates a family of proprietary sub-pixel configurations in electronic displays. It was developed in the early 1990s. This method uses the placement in a staggered manner of the five subpixels in each pixel, including two red, two green, and one central blue.

It is based on the characteristics of the retina of the human eye, which contains S (short)-cones, M (medium)-cones and L (long)-cones. Wherein, the number of S-cones significantly exceeds the number of M and L-cones. As known, S-cones provide recognition of blue color. Moreover, blue color almost does not affect the perception of brightness. In March 2008, Samsung Electronics acquired PenTile from Clairvoyante and funded Nouvoyance, Inc. to continue developing this technology. Technologically, PenTile adds subpixels to the device matrix. Modern smartphones use RGBG (additional green sub-pixel) or RGBW (additional white sub-pixel).

RGBG provides provides constant brightness while reducing the number of subpixels by 1/3 due to the high perception of green by the human eye. Today AMOLED, Super AMOLED and Super AMOLED HD often use this configuration. RGBW increases brightness without increasing power consumption and is commonly used in LTPS matrices. PenTile technology allowed Samsung to use half as many blue and red subpixels compared to green. Moreover, the most powerful blue diodes operate at half power, saving a resource. It increases their service life, and all subpixels burn out evenly. Pixel Shifting software algorithm shifts the image by 1 pixel for a prolonged static image. Recently, Google and Apple often use parallax backgrounds, preventing a static image on the screen.

AMOLED technology

Like LCD, AMOLED matrices use TFT technology. Each pixel uses its own transistor and capacitor for control. AMOLED technology has no size restrictions and is used for 10-inch screens and more. Super AMOLED is an improved version of AMOLED. They do not have an air gap between the touch layer of the screen and the matrix. In this case, the engineers integrated the sensor layer directly into the screen instead of its surface.

As a result, these screens are thinner, have less power consumption, provide absolute dust protection, a wider saturation of colors and a better image in direct sunlight. Unfortunately, they are more expensive compared to traditional AMOLED screens, and have high image grain due to the use of PenTile RGBG. A similar technology in IPS matrices is called OGS (One Glass Solution). Super AMOLED Plus and HD Super AMOLED differ only in the number of sub-pixels and, accordingly, size.

P-OLED matrices use a plastic screen backing instead of a glass. In addition to the traditional pros of OLED technology, this solution provides several additional advantages, including the ability to change the form factor of screens (flexible displays).

Samsung's latest Dynamic AMOLED version in Galaxy S10 5G is Super AMOLED with HDR10 support.

In addition, they form a less intense blue, which reduces eye strain and increases screen life.

Conclusion