Active-Matrix OLED
Encyclopedia
AMOLED is a display technology for use in mobile devices and televisions. OLED describes a specific type of thin-film display technology in which organic compound
s form the electroluminescent
material, and active matrix refers to the technology behind the addressing of pixels.
As of 2011, AMOLED technology is used in mobile phone
s, media players and digital cameras, and continues to make progress toward low-power, low-cost and large-size (for example, 40-inch) applications.
of OLED pixels that generate light upon electrical
activation that have been deposited or integrated onto a thin film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel
.
Typically, this continuous current flow is controlled by at least two TFTs at each pixel, one to start and stop the charging of a storage capacitor
and the second to provide a voltage
source at the level needed to create a constant current to the pixel and eliminating need for the very high currents required for passive matrix
OLED operation.
TFT backplane
technology is crucial in the fabrication of AMOLED displays. Two primary TFT backplane technologies, namely polycrystalline silicon
(poly-Si) and amorphous silicon
(a-Si), are used today in AMOLEDs. These technologies offer the potential for fabricating the active matrix backplanes at low temperatures (below 150°C) directly onto flexible plastic substrates for producing flexible AMOLED displays.
and Samsung
. Samsung has marketed their version of this technology as Super AMOLED
. Clear Black Display or CBD is an AMOLED display with a polarized filter on top. Researchers at DuPont
used computational fluid dynamics (CFD) software to optimize coating processes for a new solution-coated AMOLED display technology that is cost and performance competitive with existing commercial vapor deposition technology. Using custom modeling and analytical approaches, they developed short- and long-range film-thickness control and uniformity that is commercially viable at large glass sizes.
. This advantage makes active-matrix OLEDs well suited for portable electronics, where power consumption is critical to battery life.
The amount of power the display consumes varies significantly depending on the color and brightness shown. As an example, one commercial QVGA OLED display consumes 3 watts while showing black text on a white background, but only 0.7 watts showing white text on a black background. Because the black pixels actually turn off, AMOLED also has contrast ratios that are significantly better than LCD.
AMOLED displays may be difficult to view in direct sunlight compared to LCDs because of their reduced maximum brightness. Samsung's Super AMOLED
technology addresses this issue by reducing the size of gaps between layers of the screen.. Additionally, PenTile technology is sometimes used, rearranging the subpixels for each color and in the case of PenTile RGBW, adding a white subpixel, which lets through more light, thereby increasing brightness, while introducing graininess.
The organic materials used in AMOLED displays are prone to degradation over a period of time. However, technology has been developed to compensate for material degradation.
Current demand for AMOLED screens is high and, due to supply shortages of the Samsung-produced displays, certain models of HTC smartphones have been changed to use Sony's SLCD
displays in the future. Construction of new production facilities in 2011 will increase the production of AMOLED screens to cope with demand.
Phones:
Portable music players:
Games consoles:
Music production hardware:
Digital cameras:
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
s form the electroluminescent
Electroluminescence
Electroluminescence is an optical phenomenon and electrical phenomenon in which a material emits light in response to the passage of an electric current or to a strong electric field...
material, and active matrix refers to the technology behind the addressing of pixels.
As of 2011, AMOLED technology is used in mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
s, media players and digital cameras, and continues to make progress toward low-power, low-cost and large-size (for example, 40-inch) applications.
Design
An AMOLED display consists of an active matrixActive matrix
Active matrix is a type of addressing scheme used in flat panel displays. The term describes a method of switching individual elements of a flat panel display, using a CdSe or Silicon-based thin-film transistor for each pixel...
of OLED pixels that generate light upon electrical
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
activation that have been deposited or integrated onto a thin film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
.
Typically, this continuous current flow is controlled by at least two TFTs at each pixel, one to start and stop the charging of a storage capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
and the second to provide a voltage
Voltage
Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
source at the level needed to create a constant current to the pixel and eliminating need for the very high currents required for passive matrix
Passive matrix addressing
Passive matrix addressing is an addressing scheme used in earlier LCD displays, and may be used in future LCD displays. This is a matrix addressing scheme meaning that only m + n control signals are required to address a m × n display...
OLED operation.
TFT backplane
Backplane
A backplane is a group of connectors connected in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete...
technology is crucial in the fabrication of AMOLED displays. Two primary TFT backplane technologies, namely polycrystalline silicon
Polycrystalline silicon
Polycrystalline silicon, also called polysilicon, is a material consisting of small silicon crystals. It differs from single-crystal silicon, used for electronics and solar cells, and from amorphous silicon, used for thin film devices and solar cells....
(poly-Si) and amorphous silicon
Amorphous silicon
Amorphous silicon is the non-crystalline allotropic form of silicon. It can be deposited in thin films at low temperatures onto a variety of substrates, offering some unique capabilities for a variety of electronics.-Description:...
(a-Si), are used today in AMOLEDs. These technologies offer the potential for fabricating the active matrix backplanes at low temperatures (below 150°C) directly onto flexible plastic substrates for producing flexible AMOLED displays.
Future development
Manufacturers have developed in-cell touch panels, integrating the production of capacitive sensor arrays in the AMOLED module fabrication process. In-cell sensor AMOLED fabricators include AU OptronicsAU Optronics
AU Optronics was formed in December 2001 by the merger of Acer Display Technology, Inc., and Unipac Optoelectronics Corporation. In October 2006, AUO merged with Quanta Display Inc. to create a leading TFT-LCD manufacturer. Additionally, the amassed production of the company's G6 reached worldwide...
and Samsung
Samsung Electronics
Samsung Electronics is a South Korean multinational electronics and information technology company headquartered in Samsung Town, Seoul...
. Samsung has marketed their version of this technology as Super AMOLED
Super AMOLED
Super Active-Matrix Organic Light-Emitting Diode or Super AMOLED is a display technology mainly for use in mobile devices such as mobile phones...
. Clear Black Display or CBD is an AMOLED display with a polarized filter on top. Researchers at DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
used computational fluid dynamics (CFD) software to optimize coating processes for a new solution-coated AMOLED display technology that is cost and performance competitive with existing commercial vapor deposition technology. Using custom modeling and analytical approaches, they developed short- and long-range film-thickness control and uniformity that is commercially viable at large glass sizes.
Comparison to other technologies
AMOLED displays provide higher refresh rates than their passive-matrix OLED counterparts, improving response time often to under a millisecond, and they consume significantly less powerElectric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...
. This advantage makes active-matrix OLEDs well suited for portable electronics, where power consumption is critical to battery life.
The amount of power the display consumes varies significantly depending on the color and brightness shown. As an example, one commercial QVGA OLED display consumes 3 watts while showing black text on a white background, but only 0.7 watts showing white text on a black background. Because the black pixels actually turn off, AMOLED also has contrast ratios that are significantly better than LCD.
AMOLED displays may be difficult to view in direct sunlight compared to LCDs because of their reduced maximum brightness. Samsung's Super AMOLED
Super AMOLED
Super Active-Matrix Organic Light-Emitting Diode or Super AMOLED is a display technology mainly for use in mobile devices such as mobile phones...
technology addresses this issue by reducing the size of gaps between layers of the screen.. Additionally, PenTile technology is sometimes used, rearranging the subpixels for each color and in the case of PenTile RGBW, adding a white subpixel, which lets through more light, thereby increasing brightness, while introducing graininess.
The organic materials used in AMOLED displays are prone to degradation over a period of time. However, technology has been developed to compensate for material degradation.
Current demand for AMOLED screens is high and, due to supply shortages of the Samsung-produced displays, certain models of HTC smartphones have been changed to use Sony's SLCD
S-LCD
S-LCD Corporation is a joint venture between the South Korean Samsung Electronics Co. Ltd and Japanese Sony Corporation established in April 2004 in Chungcheongnam-do, South Korea....
displays in the future. Construction of new production facilities in 2011 will increase the production of AMOLED screens to cope with demand.
Uses
Commercial devices using AMOLED include:Phones:
- Dell Venue ProDell Venue ProThe Dell Venue Pro, codename Lightning, is a mobile smartphone running the Windows Phone operating system. The phone uses the T-Mobile network, but is only available for purchase at Microsoft retail stores or directly from Dell Corporation....
- Nexus OneNexus OneThe Nexus One was Google's flagship smartphone manufactured by Taiwan's HTC Corporation. It became available on January 5, 2010 and uses the Android open source mobile operating system...
- Nexus SNexus SThe Nexus S is a smartphone co-developed by Google and Samsung and manufactured by Samsung Electronics. It was the first smartphone to use the Android 2.3 "Gingerbread" operating system, and the first Android device to support Near Field Communication in both hardware and software...
(Super AMOLED) - Galaxy NexusGalaxy NexusThe Galaxy Nexus is a touchscreen slate Android smartphone developed by a partnership between Samsung and Google. The phone and operating system were developed collaboratively by engineers from both companies. It is the third generation successor to Google’s previous flagship phones, the Nexus One...
(Super AMOLED HD) - HTC DesireHTC DesireThe HTC Desire is a smartphone developed by the HTC Corporation, announced on 16 February 2010 and released in Europe and Australia in the second quarter of the same year. The HTC Desire runs the Android operating system, version 2.2 "Froyo"...
- HTC Droid Incredible
- HTC LegendHTC LegendThe HTC Legend is a phone manufactured by HTC Corporation in Taiwan for the Android platform. It was unveiled by HTC during the Mobile World Congress in Barcelona on 16 February 2010 and went on sale on 31 March 2010....
- LG Franklin Phone
- Motorola Droid RAZR (Super AMOLED Advanced)
- Nokia 700Nokia 700The Nokia 700 is a Symbian Belle ultra slim smart phone, announced on 24 August 2011. It was released in September 2011.-References:...
- Nokia C7-00Nokia C7-00The Nokia C7-00 is a Symbian^3 smartphone from the Nokia Cseries. The C7-00 features a , 640 x 360 pixel capacitive touchscreen...
- Nokia C6-01Nokia C6-01The Nokia C6-01 is a Symbian^3 smartphone from the Nokia Cseries. The C6-01 display features comes with a 3.2in AMOLED display with capacitive touchscreen capabilities and Nokia's ClearBlack technology for improved outdoor visibility...
(CBD) - Nokia E7-00Nokia E7-00The Nokia E7-00, also known as Nokia E7, is a business-oriented QWERTY smartphone by Nokia from the Nokia Eseries It was announced at Nokia world in September 2010 together with the Nokia C6-01 and Nokia C7 and started shipping in February 2011...
(CBD) - Nokia Lumia 800Nokia Lumia 800Nokia Lumia 800 is a Windows Phone OS powered smartphone, first unveiled by the company's CEO Stephen Elop, on 26 October 2011 at the Nokia World 2011 event...
- Nokia N8Nokia N8The Nokia N8 is a Symbian^3 smartphone of the Nokia Nseries and Nokia's flagship device of 2010. It was released on 23 September 2010 at the Nokia Online Store before being released in markets around the world on 1 October 2010. The N8 features a 12 megapixel camera, a pentaband 3.5G radio and...
- Nokia N85Nokia N85The Nokia N85 is a smartphone produced by Nokia. The N85's functions include those of a camera phone and portable media player, in addition to offering e-mail, web browsing, local Wi-Fi connectivity, text messaging and a built-in GPS receiver, allowing satellite navigation using no external...
- Nokia N86 8MPNokia N86 8MPThe Nokia N86 8MP is a Symbian Series 60 mobile phone. One of its main selling points is its photography features.It was Nokia's first camera phone to have an 8 megapixel sensor, and features both multiple aperture settings and a mechanical shutter , and a Carl Zeiss lens with a wide angle of view...
- Nokia N9Nokia N9The Nokia N9 is a smartphone made by Nokia based on the MeeGo "Harmattan" mobile operating system, the first from Nokia on the MeeGo OS...
(AMOLED ClearBlack) - Nokia ORO
- Nokia X7
- Orange San Francisco (Initial models)
- Samsung SGH-A877 Impression
- Samsung AMOLED Beam SPH-W9600
- Samsung Epic 4G
- Samsung i7500 GalaxySamsung I7500The Samsung i7500, known as Samsung Galaxy in some countries, is the first mobile phone manufactured by Samsung that uses the open source Android operating system. It was announced on 27 April 2009...
- Samsung Haptic Beam SPH-W7900
- Samsung SPH-m900 MomentSamsung SPH-M900The Samsung Moment, known as SPH-M900, is a smartphone manufactured by Samsung that uses the open source Android operating system.- Features :The phone features a 3.2-inch 16M-color AMOLED capacitive touch screen and a 3.2 Megapixel autofocus camera...
- Samsung i8910
- Samsung Jet
- Samsung Omnia 2
- Samsung ImpressionSamsung ImpressionThe Samsung Impression is a slider-style mobile phone manufactured by Samsung Electronics. First announced on March 30, 2009, it was released on April 7, 2009...
- Samsung RogueSamsung SCH-U960The Samsung SCH U960 is a CDMA touchscreen side-slider cell phone made by Samsung. The phone features a QWERTY keyboard, Bluetooth, MP3 Player, GPS, and a 3MP camera with Geo Tagging. It uses Verizon's EVDO Rev A data network. The Rogue runs Samsung’s TouchWiz UI with widget bar on the side...
- Samsung TransformSamsung TransformThe Samsung SPH-M920 is an Android smartphone manufactured by Samsung. It was announced on October 6, 2010 and released on October 10, 2010 for Sprint in the United States....
- Samsung Galaxy NoteSamsung Galaxy NoteThe Samsung Galaxy Note is an Android smartphone and tablet computer that was introduced in 2011. It occupies a niche in Samsung's Galaxy range, bridging the gap between other Galaxy-series smartphones such as the Galaxy S II and tablets such as the Galaxy Tab....
(Super AMOLED HD) - Samsung Galaxy S series (Super AMOLED)
- Samsung Galaxy S IISamsung Galaxy S IIThe Samsung Galaxy S II is a smartphone running under the Android operating system that was announced by Samsung on February 13, 2011 at the Mobile World Congress. It is the successor to the Samsung Galaxy S, with a different appearance and significantly improved hardware...
(Super AMOLED Plus) - Samsung Droid ChargeSamsung Droid ChargeThe Samsung Droid Charge is an Android smartphone manufactured by Samsung. It has a 1 GHz "Hummingbird" processor, front and rear cameras, and CDMA and 4G LTE radios. It was announced at CES 2011 under the name Samsung 4G LTE device. It is available from Verizon Wireless.- Processor :The...
(Super AMOLED Plus) - Samsung Wave S8500Samsung Wave S8500The Samsung Wave GT-S8500 is the first touchscreen smartphone running the new bada operating system designed by Samsung, which was commercially released on June 1, 2010...
(Super AMOLED) - Samsung S8600 Wave III (Super AMOLED)
- Samsung Stratosphere (Super AMOLED)
- Samsung FocusSamsung FocusThe Samsung Focus is a slate smartphone which runs Microsoft's Windows Phone operating system. It features a 1 GHz Qualcomm® Snapdragon™ processor, a 4.0-inch Super AMOLED screen, and 8GB of internal storage...
(Super AMOLED) - Samsung Omnia 7Samsung Omnia 7The Samsung Omnia 7 is a slate smartphone which runs Microsoft's Windows Phone operating system . It features a Qualcomm Snapdragon QSD8250 SoC clocked at 1 GHz, 4.0-inch Super AMOLED screen with a resolution of 480X800 and either 8GB or 16GB capacity of internal storage...
(Super AMOLED) - Samsung Infuse 4G (SGH-i997) (Super AMOLED Plus)
- ZTE BladeZTE BladeThe ZTE Blade , is a phone manufactured by China's ZTE Corporation for the Android platform...
(Initial Models)
Portable music players:
- Cowon S9CowonCowon Systems, Inc. is a South Korean electronics company. Established in 1995, the company's initial focus was software development. In 2000, with the introduction of the CW100, Cowon expanded their business to the portable digital audio player industry....
- Cowon J3CowonCowon Systems, Inc. is a South Korean electronics company. Established in 1995, the company's initial focus was software development. In 2000, with the introduction of the CW100, Cowon expanded their business to the portable digital audio player industry....
- Iriver Clix
- Iriver SpinnIriveririver is a consumer electronics company headquartered in South Korea and widely known for its digital audio players and other portable media devices....
- Zune HDZune HDThe Zune HD is a portable media player in the Zune product family released on September 15, 2009 by Microsoft. It is a direct competitor with the Apple iPod and iPhone series of mobile devices. It was initially released in 16 and 32 GB capacities. A 64 GB version was released on April 9, 2010...
Games consoles:
- GP2X WizGP2X WizThe GP2X Wiz is an open-source, Linux-based handheld video game console and portable media player developed by South Korean company GamePark Holdings. It was released on May 12, 2009, and was also the first console from both Game Park and Game Park Holdings to be also released outside South Korea...
- PlayStation Vita
Music production hardware:
- Dave Smith Instruments "Tempest"
- Teenage Engineering OP-1OP-1The OP-1 is a portable multi-function device incorporating a synthesizer, sampler and controller. Developed by Teenage Engineering in Stockholm, Sweden, the OP-1 was first released in 2011. The device appears in the 2010 music video for One by Swedish House Mafia.- External links :*...
Digital cameras:
- Olympus XZ-1Olympus XZ-1The Olympus XZ-1 is a high-end 10.0 megapixel compact digital camera announced and released in January 2011. Its key features are a fast f/1.8-2.5 i.Zuiko Digital lens, a built in imager shift image stabilizer and Olympus' 6 Art Filters that are also present in the E-PEN series.-Features:Key...
- Samsung EX1
- Samsung NX10Samsung NX10The Samsung NX10 is a 14.0 effective megapixel APS-C crop CMOS mirrorless interchangeable lens digital camera made by Samsung. It was announced on January 4, 2010...
- Samsung WB2000
External links
- Types of OLEDs: Passive and Active Matrix, HowStuffWorks
- A more comprehensive list of AMOLED devices, OLED-Info