iPhone

The iPhone is a line of smartphones designed and marketed by Apple Inc. The iPhone runs Apple's iOS mobile operating system, originally named iPhone OS. The first iPhone was released in 2007; the most recent iPhone, the 6th-generation iPhone 5, was released on September 21, 2012. The user interface is built around the device's multi-touch screen, including a virtual keyboard rather than a physical one. The iPhone has Wi-Fi and cellular connectivity (2G, 3G and 4G (iPhone 5 only)).

An iPhone can shoot video (though this was not a standard feature until the iPhone 3GS), take photos, play music, send and receive email, browse the web, send texts, and receive visual voicemail. Other functions — games, reference, GPS navigation, social networking, etc. — can be enabled by downloading apps; as of 2012, the App Store offered more than 700,000 apps by Apple and third parties.

iOS 6 Features

Beautifully designed from the ground up (and the sky down), Maps changes the way you see the world. Map elements are vector based, so graphics and text are incredibly detailed — even when you zoom all the way in — and panning is smooth. Tilt and rotate to view an area, and Maps keeps the names of streets and places where they belong. Get visual and spoken turn-by-turn navigation and real-time traffic updates. Even soar over cityscapes to see the sights from the air in amazing, high-resolution quality.

IOS 6

HISTORY

iOS 6 was previewed on June 11, 2012 during WWDC 2012, with release announced for Fall 2012. Following the pattern of previous iOS releases, older devices are no longer supported, specifically the iPod Touch (3rd generation) and the iPad (original). Supported devices on this release include the iPhone 3GS onwards, the iPod Touch (4th generation) onwards, and the iPad 2 onwards.

IOS (Iphone Operating System)

iOS (previously iPhone OS) is a mobile operating system developed and distributed by Apple Inc. Originally released in 2007 for the iPhone and iPod Touch, it has been extended to support other Apple devices such as the iPad and Apple TV. Unlike Microsoft's Windows CE (Windows Phone) and Google's Android, Apple does not license iOS for installation on non-Apple hardware. As of September 12, 2012, Apple's App Store contained more than 700,000 iOS applications, which have collectively been downloaded more than 30 billion times. It had a 23% share of the smartphone operating system units sold in the first quarter of 2012, behind only Google's Android. In June 2012, it accounted for 65% of mobile web data consumption (including use on both the iPod Touch and the iPad). At the half of 2012, there were 410 million devices activated. According to the special media event held by Apple on September 12, 2012, 400 million devices have been sold through June 2012.

Bluetooth V4.0

The Bluetooth SIG completed the Bluetooth Core Specification version 4.0, which includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy protocols. Bluetooth high speed is based on Wi-Fi, and Classic Bluetooth consists of legacy Bluetooth protocols. This version has been adopted as of June 30, 2010.

Bluetooth low energy (BLE), previously known as WiBree, is a subset to Bluetooth v4.0 with an entirely new protocol stack for rapid build-up of simple links. As an alternative to the Bluetooth standard protocols that were introduced in Bluetooth v1.0 to v3.0, it is aimed at very low power applications running off a coin cell. Chip designs allow for two types of implementation, dual-mode, single-mode and enhanced past versions. The provisional names Wibree and Bluetooth ULP (Ultra Low Power) were abandoned and the BLE name was used for a while. In late 2011, new logos “Bluetooth Smart Ready” for hosts and “Bluetooth Smart” for sensors were introduced as the general-public face of BLE.

• In a single mode implementation the low energy protocol stack is implemented solely. CSR, Nordic Semiconductor and Texas Instruments have released single mode Bluetooth low energy solutions.
• In a dual-mode implementation, Bluetooth low energy functionality is integrated into an existing Classic Bluetooth controller. Currently (2011-03) the following semiconductor companies have announced the availability of chips meeting the standard: Atheros, CSR, Broadcom and Texas Instruments. The compliant architecture shares all of Classic Bluetooth’s existing radio and functionality resulting in a negligible cost increase compared to Classic Bluetooth.

Cost-reduced single-mode chips, which enable highly integrated and compact devices, feature a lightweight Link Layer providing ultra-low power idle mode operation, simple device discovery, and reliable point-to-multipoint data transfer with advanced power-save and secure encrypted connections at the lowest possible cost.

General improvements in version 4.0 include the changes necessary to facilitate BLE modes, as well the Generic Attribute Profile (GATT) and Security Manager (SM) services with AES Encryption.

Core Specification Addendum 2 was unveiled in December 2011; it contains improvements to the audio Host Controller Interface and to the High Speed (802.11) Protocol Adaptation Layer.

Source : Wikipedia

Bluetooth V3.0 + HS

Version 3.0 + HS of the Bluetooth Core Specification was adopted by the Bluetooth SIG on April 21, 2009. Bluetooth 3.0+HS provides theoretical data transfer speeds of up to 24 Mbit/s, though not over the Bluetooth link itself. Instead, the Bluetooth link is used for negotiation and establishment, and the high data rate traffic is carried over a collocated 802.11 link.

The main new feature is AMP (Alternate MAC/PHY), the addition of 802.11 as a high speed transport. The High-Speed part of the specification is not mandatory, and hence only devices sporting the "+HS" will actually support the Bluetooth over 802.11 high-speed data transfer. A Bluetooth 3.0 device without the "+HS" suffix will not support High Speed, and needs to only support a feature introduced in Core Specification Version 3.0  or earlier Core Specification Addendum 1.

L2CAP Enhanced modes

    Enhanced Retransmission Mode (ERTM) implements reliable L2CAP channel, while Streaming Mode (SM) implements unreliable channel with no retransmission or flow control. Introduced in Core Specification Addendum 1.

Alternate MAC/PHY

    Enables the use of alternative MAC and PHYs for transporting Bluetooth profile data. The Bluetooth radio is still used for device discovery, initial connection and profile configuration, however when large quantities of data need to be sent, the high speed alternate MAC PHY 802.11 (typically associated with Wi-Fi) will be used to transport the data. This means that the proven low power connection models of Bluetooth are used when the system is idle, and the faster radio is used when large quantities of data need to be sent. AMP links require enhanced L2CAP modes.

Unicast Connectionless Data

    Permits service data to be sent without establishing an explicit L2CAP channel. It is intended for use by applications that require low latency between user action and reconnection/transmission of data. This is only appropriate for small amounts of data.

Enhanced Power Control

    Updates the power control feature to remove the open loop power control, and also to clarify ambiguities in power control introduced by the new modulation schemes added for EDR. Enhanced power control removes the ambiguities by specifying the behaviour that is expected. The feature also adds closed loop power control, meaning RSSI filtering can start as the response is received. Additionally, a "go straight to maximum power" request has been introduced. This is expected to deal with the headset link loss issue typically observed when a user puts their phone into a pocket on the opposite side to the headset.

Ultra-wideband

The high speed (AMP) feature of Bluetooth v3.0 was originally intended for UWB, but the WiMedia Alliance, the body responsible for the flavor of UWB intended for Bluetooth, announced in March 2009 that it was disbanding, and ultimately UWB was omitted from the Core v3.0 specification.

On March 16, 2009, the WiMedia Alliance announced it was entering into technology transfer agreements for the WiMedia Ultra-wideband (UWB) specifications. WiMedia has transferred all current and future specifications, including work on future high speed and power optimized implementations, to the Bluetooth Special Interest Group (SIG), Wireless USB Promoter Group and the USB Implementers Forum. After the successful completion of the technology transfer, marketing and related administrative items, the WiMedia Alliance will cease operations.

In October 2009 the Bluetooth Special Interest Group suspended development of UWB as part of the alternative MAC/PHY, Bluetooth v3.0 + HS solution. A small, but significant, number of former WiMedia members had not and would not sign up to the necessary agreements for the IP transfer. The Bluetooth SIG is now in the process of evaluating other options for its longer term roadmap.

Source : Wikipedia

Implementation of Bluetooth

Bluetooth uses a radio technology called frequency-hopping spread spectrum, which chops up the data being sent and transmits chunks of it on up to 79 bands (1 MHz each; centered from 2402 to 2480 MHz) in the range 2,400–2,483.5 MHz (allowing for guard bands). This range is in the globally unlicensed Industrial, Scientific and Medical (ISM) 2.4 GHz short-range radio frequency band. It usually performs 800 hops per second, with AFH enabled.

Originally Gaussian frequency-shift keying (GFSK) modulation was the only modulation scheme available; subsequently, since the introduction of Bluetooth 2.0+EDR, π/4-DQPSK and 8DPSK modulation may also be used between compatible devices. Devices functioning with GFSK are said to be operating in basic rate (BR) mode where an instantaneous data rate of 1 Mbit/s is possible. The term Enhanced Data Rate (EDR) is used to describe π/4-DPSK and 8DPSK schemes, each giving 2 and 3 Mbit/s respectively. The combination of these (BR and EDR) modes in Bluetooth radio technology is classified as a "BR/EDR radio".

Bluetooth is a packet-based protocol with a master-slave structure. One master may communicate with up to 7 slaves in a piconet; all devices share the master's clock. Packet exchange is based on the basic clock, defined by the master, which ticks at 312.5 µs intervals. Two clock ticks make up a slot of 625 µs; two slots make up a slot pair of 1250 µs. In the simple case of single-slot packets the master transmits in even slots and receives in odd slots; the slave, conversely, receives in even slots and transmits in odd slots. Packets may be 1, 3 or 5 slots long but in all cases the master transmit will begin in even slots and the slave transmit in odd slots.

Bluetooth provides a secure way to connect and exchange information between devices such as faxes, mobile phones, telephones, laptops, personal computers, printers, Global Positioning System (GPS) receivers, digital cameras, and video game consoles.

Communication and connection

A master Bluetooth device can communicate with a maximum of seven devices in a piconet (an ad-hoc computer network using Bluetooth technology), though not all devices reach this maximum. The devices can switch roles, by agreement, and the slave can become the master (for example, a headset initiating a connection to a phone will necessarily begin as master, as initiator of the connection; but may subsequently prefer to be slave).

The Bluetooth Core Specification provides for the connection of two or more piconets to form a scatternet, in which certain devices simultaneously play the master role in one piconet and the slave role in another.

At any given time, data can be transferred between the master and one other device (except for the little-used broadcast mode). The master chooses which slave device to address; typically, it switches rapidly from one device to another in a round-robin fashion. Since it is the master that chooses which slave to address, whereas a slave is (in theory) supposed to listen in each receive slot, being a master is a lighter burden than being a slave. Being a master of seven slaves is possible; being a slave of more than one master is difficult. The specification is vague as to required behaviour in scatternets.

Many USB Bluetooth adapters or "dongles" are available, some of which also include an IrDA adapter. Older (pre-2003) Bluetooth dongles, however, have limited capabilities, offering only the Bluetooth Enumerator and a less-powerful Bluetooth Radio incarnation. Such devices can link computers with Bluetooth with a distance of 100 meters, but they do not offer as many services as modern adapters do.

BLUETOOTH 3.0

Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the ISM band from 2400–2480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Created by telecoms vendor Ericsson in 1994, it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization.

Bluetooth is managed by the Bluetooth Special Interest Group, which has more than 16,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The SIG oversees the development of the specification, manages the qualification program, and protects the trademarks. To be marketed as a Bluetooth device, it must be qualified to standards defined by the SIG. A network of patents is required to implement the technology and are licensed only for those qualifying devices; thus the protocol, whilst open, may be regarded as proprietary.

Name and logo

The word "Bluetooth" is an anglicised version of the Scandinavian Blåtand/Blåtann, the epithet of the tenth-century king Harald I of Denmark and parts of Norway who united dissonant Danish tribes into a single kingdom. The idea of this name was proposed by Jim Kardach who developed a system that would allow cell phones to communicate with computers (at the time he was reading Frans Gunnar Bengtsson's historical novel The Long Ships about Vikings and king Harald Bluetooth) The implication is that Bluetooth does the same with communications protocols, uniting them into one universal standard.

The Bluetooth logo is a bind rune merging the Younger Futhark runes  (Hagall) (*) and  (Bjarkan) (ᛒ), Harald's initials.

Source : Wikipedia

Windows Phone 7.5 (Operating system)

Windows Phone 7.5

7.10.7720 "Windows Phone 7.5" codename "Mango" was announced in February 2011 at the Mobile World Congress. The update was formally announced in New York on May 24, 2011, when Microsoft gave an in-depth preview of the update, shortly before which Steve Ballmer had disclosed that there would be over 500 features. Although the OS internally identifies itself as version 7.1, it is marketed as version 7.5 in all published materials intended for end-users.

Microsoft started rolling out Windows Phone 7.5 to both the United States and International markets on September 27, 2011. The first phones that came pre-loaded with Windows Phone 7.5 were released in the last quarter of 2011.

Messaging and social integration

• Dynamic Live tile information
• Twitter and LinkedIn integration in the People hub.
• Groups: organize contacts by groups which can also be pinned on the start screen.
• Contact cards now include all the contacts conversation history (SMS, emails, MMS, Messenger, etc.)
• Facebook Places check-in support.
• Windows Live Messenger and Facebook Chat integration.
• Threads: all messaging communication organized in a single thread (Messenger, SMS, MMS).
• Threaded email conversations support.
• Outlook tasks support.
• Facebook events integrated into the calendar.
• Linked email accounts: multiple email accounts can be combined and linked into one inbox.[5]
• Built-in voice-to-text/text-to-voice functionality, which will allow for hands-free texting or chatting.
• Server search for Exchange.
• Information Rights Management support for emails and Office documents.
• Visual Voicemail

Search/Bing

• Bing Vision: barcode, covers, posters, products scanning, and OCR text translation.
• Bing Audio / Music: Shazam-like audio recognition.
• Bing Local Scout: "around me" business and POI locator.
• Bing Quick Cards: product/media information, reviews.
• Bing Search: indoor maps (US only), image search results, third-party app integration.
• Bing Maps: turn-by-turn navigation, voice guidance.

Office

• Skydrive and Office 365 documents sync (PDF also supported).
• Excel Mobile now supports adding additional macro functions.
• Microsoft Lync support via downloadable app.
• Added "To-Do" option when editing OneNote pages.
• Removed ability to edit Office documents from versions older than Office 2007.

Photo management

• People / Groups gallery with Skydrive and Facebook sync.
• People tagging in the photos with Skydrive and Facebook sync.
• Photo auto-fix - automatically improves sharpness, brightness, etc.
• Pictures tile is now animated.
• Video sharing via MMS, Facebook, Skydrive, and email.
• Twitter integration—Tweet your pics!
• Integration with the People Hub.
• Quick access to the Camera Roll.
• When you choose a photo from within an app, you can now pick from online albums on Facebook or SkyDrive, not just pictures saved on your phone.
• Pin any album to Start, including Facebook albums.

Multimedia

• Zune SmartDJ mix support.
• Artist picture now displays on lock screen when music is played.
• UI change of the media controls on the lock screen.
• Ability to control video aspect ratio during playback.
• Single music track repeat without having to pin it on the start screen.
• Podcast downloads / subscriptions over the air (US only).
• Open / play media content by voice.
• Ability to create and save playlists.

Marketplace

• Revamped Marketplace UI and search.

Camera

• UI changes (new icons + added arrow icon on the lower left of the viewfinder to indicate camera roll).
• Settings are now saved when the Camera application is closed.
• Disable/enable shutter sound.
• Support for front facing camera.
• Touch focus and capture—Tap any spot on the screen to focus there and take the shot. (This varies according to hardware—some phones will have tap-to-capture but will still automatically center focus.)
• Review pictures above the lock—Snap a photo when your phone is locked, then take a peek at it above the lock. You’ll only be able to get to photos you just took—better for security.
• Changes for portrait orientation—Now, when you take a picture in portrait orientation, you’ll see it in portrait orientation when you review it.

Games

• Redesigned Games hub with integrated 3D avatar and avatar customization.
• Friends and achievements now integrated in the hub.
• Fast Async for multiplayer games.

Internet Explorer 9 Mobile

• Hardware-accelerated rendering.
• Support for HTML5 audio and video playback.
• Background HTML5 audio playback.
• Geolocation support.
• New JavaScript engine.
• New UI with URL bar at the bottom of the screen.
• URL bar is now available in landscape mode.
• Removal of Find on Page feature
• Moved the "tabs" button to a menu item under the application bar.

Security

• Voice commands are now disabled when the device is locked.
• Complex (alpha-numeric) PIN support.

Other changes

• Internet sharing
• Battery saver: phone automatically disables power consuming services and applications running in the background if the battery is low. Also predicts time remaining on battery.
• Ringtone manager with custom and downloadable ringtones.
• The "People" tile has been reworked and is animated differently than before.
• Search icon and quick jump list added to the application list.
• Support for 16 new languages: Czech, Danish, Hungarian, Dutch (Netherlands), Norwegian, Polish, Portuguese (Brazil, Portugal), Finnish, Swedish, Greek, Russian, Korean, Chinese (Traditional, Simplified), Japanese.
• East Asian handwriting recognition.
• Support for new languages and emoticons in on-screen keyboard.
• Hidden WiFi network support.
• Qualcomm MSM7X30 and MSM8X55 support.
• Programs menu will have alphabetical options similar to the people functionality
• Power off now requires a swipe down gesture after holding down the power button for a few seconds.
• Removal of "soft-on" alarm feature
• Modification of alarm sleep interval

Development API changes and additions

• Third-party application multi-tasking and fast application switching.
• Support for background tasks and services/agents.
• Expanded live tiles that can be updated without network connection and can have two sides which flip periodically.
• App Connect: third-party applications can integrate with Bing search, have multiple live tiles, and can have push notifications that link deep ("Deep Toast") into various parts of the application directly.
• Optional 32 bit color support for Silverlight applications with hardware dithering.
• Silverlight 4 support.
• Silverlight + XNA support in the same application screen.
• Raw camera feed access for third-party applications.
• New sensor API combines compass, gyroscope, and accelerometer.
• Improved Listbox control with better scrolling performance.
• Improved WebBrowser control with IE9 rendering engine and system-wide cookies access.
• Clipboard API.
• Hardware-accelerated video decoding in the MediaPlayer control.
• TCP/IP and UDP sockets support.
• Embedded database with LINQ (based on SQL Server Compact 4.0 engine, but without direct SQL execution).
• Background file transfer agent.
• Generational garbage collector.
• NEON/SIMD support for XNA applications.

Source : Wikipedia

Android (Operating System)

Android is a Linux-based operating system for mobile devices such as smartphones and tablet computers, developed by Google in conjunction with the Open Handset Alliance. Android was initially developed by Android Inc, whom Google financially backed and later purchased in 2005. The unveiling of the Android distribution in 2007 was announced with the founding of the Open Handset Alliance, a consortium of 86 hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices. Google releases the Android code as open-source, under the Apache License. The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android.

Android has a large community of developers writing applications ("apps") that extend the functionality of the devices. Developers write primarily in a customized version of Java, and apps can be downloaded from online stores such as Google Play (formerly Android Market), the app store run by Google, or third-party sites. In June 2012, there were more than 600,000 apps available for Android, and the estimated number of applications downloaded from Google Play was 20 billion.

Android became the world’s leading smartphone platform at the end of 2010. For the first quarter of 2012, Android had a 59% smartphone market share worldwide.As of third quarter 2012, there were 480 million devices activated and 1.3 million activations per day.

Sony Xperia Tipo

Sony Xperia tipo is a low-range Android smartphone manufactured by Sony Mobile Communications. The device was released globally during August 2012. There would be a dual sim card version of the Xperia tipo available in certain countries known as the Xperia tipo dual. Other than having another sim card slot, the Xperia tipo and Xperia tipo dual has the same hardware and software. However, the Xperia tipo dual will only be available in black and silver.

Samsung I7500 Galaxy

The 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. It is succeeded by the Samsung i5700.

Nokia Lumina 900

Nokia Lumia 900 is a Windows Phone-powered smartphone, first unveiled on January 9, 2012 by Nokia at Consumer Electronics Show 2012, where it won the Best Smartphone award in January 2012. The phone has 4G LTE support and was released in April, 2012. Nokia Lumia 900 has a 4.3″ (109 mm) display and a ClearBlack AMOLED 800×480 capacitive touchscreen. It also features a one-piece polycarbonate body and is available in magenta, black, cyan and white.

DROIDE RAZR

The Motorola Droid Razr (GSM/UMTS version: Motorola Razr; both versions styled RAZR) is an Android-based, 4G LTE-capable smartphone designed by Motorola that launched on Verizon Wireless on November 11, 2011. It was announced on 18 October 2011 in New York City.

At launch, the RAZR was the thinnest smartphone in the world at only 7.1 mm thick on most of the device (it does, however, have a "bump" on top that's approximately 11.1 mm thick.) and includes a 4.3-inch (110 mm) super active-matrix organic light emitting diode (AMOLED) advanced PenTile display, covered in a Gorilla glass screen and a kevlar back plate. It is powered by an OMAP 4430 SoC with dual 1.2 GHz ARM Cortex-A9 processor cores. Its 8 megapixel rear facing camera can record 1080p HD videos. It comes with 1 GB of RAM and runs Android version 4.0.4

AMOLED Categories

Super AMOLED
Super AMOLED is Samsung's term for an AMOLED display with an integrated digitizer, meaning, the layer that detects touch is integrated into the screen, rather than being overlaid on top of it. According to Samsung, Super AMOLED reflects 5 times less sunlight compared to the first generation AMOLED. The display technology itself is not changed. Also, Super AMOLED displays uses a PenTile RGBG subpixel arrangement that has fewer subpixels than a traditional RGB RGB subpixel arrangement.


Super AMOLED Advanced
Super AMOLED Advanced is a term marketed by Motorola to describe a brighter display than Super AMOLED screens, but also a higher resolution – qHD or 960 × 540 for Super AMOLED Advanced compared to WVGA or 800 × 480 for Super AMOLED. This display equips the Motorola Droid RAZR.

Super AMOLED Plus

Super AMOLED Plus, first introduced with the Samsung Galaxy S II and Samsung Droid Charge smartphones, is a branding from Samsung where the PenTile RGBG pixel matrix (2 subpixels) used in Super AMOLED displays has been replaced with a traditional RGB RGB (3 subpixels) arrangement typically used in LCD displays. This variant of AMOLED is brighter and therefore more energy efficient than Super AMOLED displays and produces a sharper, less grainy image because of the increased number of subpixels. In comparison to AMOLED and Super AMOLED displays, the Super AMOLED Plus displays are even more energy efficient and brighter.

HD Super AMOLED

HD Super AMOLED is a branding from Samsung for an HD-resolution (>1280×720) Super AMOLED display. The first device to use it was the Samsung Galaxy Note. the Galaxy Note and the Galaxy S III both implements the HD Super AMOLED with a PenTile RGBG-matrix (2 subpixels/pexel) , while the Galaxy Note II uses an RBG matrix (3 subpixels/pixels) but not in the standard 3 stripe arrangement.

Source : Wikipedia

AMOLED Compare with Other Technologies

AMOLED displays provide higher refresh rates than their passive-matrix OLED counterparts[not specific enough to verify], improving response time often to under a millisecond, and they consume significantly less power. 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 colour 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 with 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 often used to allow for a higher resolution display while requiring fewer subpixels than would otherwise be needed, often resulting in a display less sharp and more grainy compared with a non-pentile display with the same resolution.

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 next-generation LCD displays from the Samsung and Sony joint-venture SLCD in the future. Construction of new production facilities in 2011 will increase the production of AMOLED screens to cope with demand.

Source : Wikipedia

AMOLED 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 Optronics and Samsung. Samsung has marketed their version of this technology as Super AMOLED. 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 chemical vapor deposition (CVD) 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.

Source : Wikipedia

AMOLED - ACTIVE MATRIX ORGANIC LIGHT-EMITTING DIODE

ACTIVE MATRIX ORGANIC LIGHT-EMITTING DIODE

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 compounds form the electroluminescent material, and active matrix refers to the technology behind the addressing of pixels.

As of 2012, AMOLED technology is used in mobile phones, 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 matrix of OLED pixels that generate light (luminescence) 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 (to trigger the luminescence), with one TFT 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, thereby eliminating the 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.

Source : Wikipedia

LG - 4mm Thick OLED TV

LG to Launch a Futuristic 4mm-thick OLED TV at CES
by Abigail Phillips

LG has revealed it will be officially launching a futuristic 55 inch OLED TV at the Consumer Electronics Show in Las Vegas next week that is just 4mm thick. 

Using the same technology as the latest smartphone screens, the OLED TV can produce a resolution higher than any other TV of the same size. The 'organic light-emitting diode' (OLED) system makes images appear significantly smoother owing to the fact it offers a 'refresh-rate' that is 1,000 times faster than most current sets on the market.

 

Furthermore, LG states that “OLED TV generated the most natural colours of any TV set at a much lower price point that could have been achieved using the standard manufacturing process.”

 

The OLED TV generates a wider spectrum of colours by offering four additional colours for its pixels alongside the usual three; it will add white to the conventional red, green and blue. This will give the images a lot more depth and fluidity.

 

The bezel of the OLED TV is also so thin, that the image appears almost across the entire frontage of the device, which also adds to the viewing experience.

 

Havis Kwon, President and CEO of LG Electronics Home Entertainment Company said that “OLED is clearly the future of home TV entertainment and LG is very focused on making this exciting technology as easy as possible for consumers to embrace.”

 

As yet there is no word on the cost or availability of the OLED TV.

Source : Business Review Europe

Advantages & Disadvantages of OLED

ADVANTAGES

The different manufacturing process of OLEDs lends itself to several advantages over flat panel displays made with LCD technology.

1. Lower cost in the future

    OLEDs can be printed onto any suitable substrate by an inkjet printer or even by screen printing, theoretically making them cheaper to produce than LCD or plasma displays. However, fabrication of the OLED substrate is more costly than that of a TFT LCD, until mass production methods lower cost through scalability. Roll-roll vapour-deposition methods for organic devices do allow mass production of thousands of devices per minute for minimal cost, although this technique also induces problems in that multi-layer devices can be challenging to make due to registration issues, lining up the different printed layers to the required degree of accuracy.

2. Light weight & flexible plastic substrates

    OLED displays can be fabricated on flexible plastic substrates leading to the possibility of flexible organic light-emitting diodes being fabricated or other new applications such as roll-up displays embedded in fabrics or clothing. As the substrate used can be flexible such as PET, the displays may be produced inexpensively.

3. Wider viewing angles & improved brightness

    OLEDs can enable a greater artificial contrast ratio (both dynamic range and static, measured in purely dark conditions) and viewing angle compared to LCDs because OLED pixels directly emit light. OLED pixel colours appear correct and unshifted, even as the viewing angle approaches 90° from normal.

4. Better power efficiency

    LCDs filter the light emitted from a backlight, allowing a small fraction of light through so they cannot show true black, while an inactive OLED element does not produce light or consume power.

5. Response time

    OLEDs can also have a faster response time than standard LCD screens. Whereas LCD displays are capable of between 2 and 16 ms response time offering a refresh rate of 60 to 480 Hz, an OLED can theoretically have less than 0.01 ms response time, enabling up to 100,000 Hz refresh rate.

DISADVANTAGES

1. Current costs
    OLED manufacture currently requires process steps that make it extremely expensive. Specifically, it requires the use of Low-Temperature Polysilicon backplanes; LTPS backplanes in turn require laser annealing from an amorphous silicon start, so this part of the manufacturing process for AMOLEDs starts with the process costs of standard LCD, and then adds an expensive, time-consuming process that cannot currently be used on large-area glass substrates.

2. Lifespan
    The biggest technical problem for OLEDs was the limited lifetime of the organic materials. In particular, blue OLEDs historically have had a lifetime of around 14,000 hours to half original brightness (five years at 8 hours a day) when used for flat-panel displays. This is lower than the typical lifetime of LCD, LED or PDP technology—each currently rated for about 25,000–40,000 hours to half brightness, depending on manufacturer and model. However, some manufacturers' displays aim to increase the lifespan of OLED displays, pushing their expected life past that of LCD displays by improving light outcoupling, thus achieving the same brightness at a lower drive current. In 2007, experimental OLEDs were created which can sustain 400 cd/m2 of luminance for over 198,000 hours for green OLEDs and 62,000 hours for blue OLEDs.

3. Color balance issues
    Additionally, as the OLED material used to produce blue light degrades significantly more rapidly than the materials that produce other colors, blue light output will decrease relative to the other colors of light. This variation in the differential color output will change the color balance of the display and is much more noticeable than a decrease in overall luminance. This can be partially avoided by adjusting colour balance but this may require advanced control circuits and interaction with the user, which is unacceptable for some users. In order to delay the problem, manufacturers bias the colour balance towards blue so that the display initially has an artificially blue tint, leading to complaints of artificial-looking, over-saturated colors. More commonly, though, manufacturers optimize the size of the R, G and B subpixels to reduce the current density through the subpixel in order to equalize lifetime at full luminance. For example, a blue subpixel may be 100% larger than the green subpixel. The red subpixel may be 10% smaller than the green.

4. Efficiency of blue OLEDs
    Improvements to the efficiency and lifetime of blue OLEDs is vital to the success of OLEDs as replacements for LCD technology. Considerable research has been invested in developing blue OLEDs with high external quantum efficiency as well as a deeper blue color. External quantum efficiency values of 20% and 19% have been reported for red (625 nm) and green (530 nm) diodes, respectively. However, blue diodes (430 nm) have only been able to achieve maximum external quantum efficiencies in the range of 4% to 6%.

5. Water damage
    Water can damage the organic materials of the displays. Therefore, improved sealing processes are important for practical manufacturing. Water damage may especially limit the longevity of more flexible displays.

6. Outdoor performance
    As an emissive display technology, OLEDs rely completely upon converting electricity to light, unlike most LCDs which are to some extent reflective; e-ink leads the way in efficiency with ~ 33% ambient light reflectivity, enabling the display to be used without any internal light source. The metallic cathode in an OLED acts as a mirror, with reflectance approaching 80%, leading to poor readability in bright ambient light such as outdoors. However, with the proper application of a circular polarizer and anti-reflective coatings, the diffuse reflectance can be reduced to less than 0.1%. With 10,000 fc incident illumination (typical test condition for simulating outdoor illumination), that yields an approximate photopic contrast of 5:1.

7. Power consumption
    While an OLED will consume around 40% of the power of an LCD displaying an image which is primarily black, for the majority of images it will consume 60–80% of the power of an LCD: however it can use over three times as much power to display an image with a white background such as a document or website. This can lead to reduced real-world battery life in mobile devices when white backgrounds are used. 

Source : Wikipedia

OLED Device Architectures

Structure

1. Bottom or Top Emission

Bottom emission devices use a transparent or semi-transparent bottom electrode to get the light through a transparent substrate. Top emission devices use a transparent or semi-transparent top electrode emitting light directly. Top-emitting OLEDs are better suited for active-matrix applications as they can be more easily integrated with a non-transparent transistor backplane.

2. Transparent OLEDs

Transparent OLEDs use transparent or semi-transparent contacts on both sides of the device to create displays that can be made to be both top and bottom emitting (transparent). TOLEDs can greatly improve contrast, making it much easier to view displays in bright sunlight. This technology can be used in Head-up displays, smart windows or augmented reality applications.

3. Graded Heterojunction

Graded heterojunction OLEDs gradually decrease the ratio of electron holes to electron transporting chemicals. This results in almost double the quantum efficiency of existing OLEDs

4. Stacked OLEDs

Stacked OLEDs use a pixel architecture that stacks the red, green, and blue subpixels on top of one another instead of next to one another, leading to substantial increase in gamut and color depth, and greatly reducing pixel gap. Currently, other display technologies have the RGB (and RGBW) pixels mapped next to each other decreasing potential resolution.

5. Inverted OLED

In contrast to a conventional OLED, in which the anode is placed on the substrate, an Inverted OLED uses a bottom cathode that can be connected to the drain end of an n-channel TFT especially for the low cost amorphous silicon TFT backplane useful in the manufacturing of AMOLED displays.

Patterning Technologies

Patternable organic light-emitting devices use a light or heat activated electroactive layer. A latent material (PEDOT-TMA) is included in this layer that, upon activation, becomes highly efficient as a hole injection layer. Using this process, light-emitting devices with arbitrary patterns can be prepared.

Colour patterning can be accomplished by means of laser, such as radiation-induced sublimation transfer (RIST).

Organic vapour jet printing (OVJP) uses an inert carrier gas, such as argon or nitrogen, to transport evaporated organic molecules (as in Organic Vapor Phase Deposition). The gas is expelled through a micron sized nozzle or nozzle array close to the substrate as it is being translated. This allows printing arbitrary multilayer patterns without the use of solvents.

Conventional OLED displays are formed by vapor thermal evaporation (VTE) and are patterned by shadow-mask. A mechanical mask has openings allowing the vapor to pass only on the desired location.

Backplane Technologies

For a high resolution display like a TV, a TFT backplane is necessary to drive the pixels correctly. Currently, Low Temperature Polycrystalline silicon LTPS-TFT is used for commercial AMOLED displays. LTPS-TFT has variation of the performance in a display, so various compensation circuits have been reported. Due to the size limitation of the excimer laser used for LTPS, the AMOLED size was limited. To cope with the hurdle related to the panel size, amorphous-silicon/microcrystalline-silicon backplanes have been reported with large display prototype demonstrations.

Source: Wikipedia