The iPad is a line of tablet computers designed, developed and marketed by Apple Inc. primarily as a platform for audio-visual media including books, periodicals, movies, music, games, and web content. Its size and weight falls between those of contemporary smartphones and laptop computers. The iPad runs the same operating system as the iPod Touch and iPhone—and can run its own applications as well as iPhone applications. Without modification, and with the exception of websites, it will only run programs approved by Apple and distributed via its online store.
Like iPhone and iPod Touch, the iPad is controlled by a multitouch display—a departure from most previous tablet computers, which used a pressure-triggered stylus—as well as a virtual onscreen keyboard in lieu of a physical keyboard. The iPad uses a Wi-Fi data connection to browse the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to HSPA or EV-DO data networks. The device is managed and synced by iTunes on a personal computer via USB cable.
Apple released the first iPad in April 2010, and sold 3 million of the devices in 80 days. During 2010, Apple sold 14.8 million iPads worldwide, representing 75 percent of tablet PC sales at the end of 2010. By the release of the iPad 2 in March 2011, more than 15 million iPads had been sold— more than all other tablet PCs combined. In 2011, it is expected to take 83 percent of the tablet computing market share in the United States
The iPad's touchscreen display is a 9.7 in (25 cm) liquid crystal display (1024 × 768 pixels) with fingerprint-resistant and scratch-resistant glass. Steve Jobs backed the choice of screen size, saying a 7-inch screen would be "too small to express the software." He said 10 inches was the minimum for a tablet screen. Like the iPhone, the iPad is designed to be controlled by bare fingers; normal gloves and styli that prevent electrical conductivity may not be used, although there are special gloves and capacitive styli designed for this use.
The display responds to other sensors: an ambient light sensor to adjust screen brightness and a 3-axis accelerometer to sense iPad orientation and switch between portrait and landscape modes. Unlike the iPhone and iPod touch built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad built-in applications support screen rotation in all four orientations, including upside-down. Consequently, the device has no intrinsic "native" orientation; only the relative position of the home button changes. The iPad 2 added a 3-axis gyroscope that is used only third party apps, usually games.
There are four physical switches on the iPad, including a home button near the display that returns the user to the main menu, and three plastic physical switches on the sides: wake/sleep and volume up/down, plus a third which, whose function has changed with software updates. Originally, the switch would lock the screen to its current orientation, but the iOS 4.2 changed it to a mute switch, with rotation lock now available in an onscreen menu. In the iOS 4.3 update, released with the iPad 2, a setting was added to allow the user to specify whether the side switch was used for rotation lock or mute.
Apple reduced the size of the iPad 2 by 33% compared to its predecessor by eliminating the stamped sheet metal frame from the display, integrating new thinner glass technology for the touch screen overlay, and slightly reducing the space between the display and battery. The iPad 2's screen is thinner, lighter, and yet stronger than the original iPad's.
The original iPad had no camera. The iPad 2 has front VGA camera and a rear-facing 720p camera, both capable of still images and 30fps video. The rear facing camera has a 5x digital zoom for still images only. Both shoot photo and video in a 4:3 fullscreen aspect ratio, unlike the iPhone 4, which shoots in a 16:9 widescreen aspect ratio. It also lacks the iPhone's tap to focus feature. The cameras allow FaceTime video messaging with iPhone 4, iPod Touch 4, and Snow Leopard Macs
ConnectivityThe iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Maps. The 3G model contains A-GPS to allow its position to be calculated with GPS or relative to nearby cellphone towers; it also has a black plastic accent on the back side to improve 3G radio sensitivity.
For wired connectivity, the iPad has only a TRRS headphone jack and a proprietary Apple dock connector; it lacks the Ethernet and USB ports of larger computers.
Audio and outputthe iPad has two internal mono speakers located on the bottom-right of the unit. In the original iPad, the speakers push sound through two small sealed channels leading to the three audio ports carved into the device, while the iPad 2 has its speakers behind a single grill.
A volume switch is on the right side of the unit. A 3.5-mm TRRS connector audio-out jack on the top-left corner of the device provides stereo sound for headphones with or without microphones and/or volume controls. The iPad also contains a microphone that can be used for voice recording.
The built-in Bluetooth 2.1 + EDR interface allows wireless headphones and keyboards to be used with the iPad. However, the iOS does not currently support file transfer via Bluetooth. iPad also features 1024 x 768 VGA video output for limited applications, screen capture, connecting an external display or television through an accessory adapter.
Power and batteryThe iPad uses an internal rechargeable lithium-ion polymer battery (LiPo). The batteries are made in Taiwan by Simplo Technology, which makes 60% of them, and Dynapack International Technology. The iPad is designed to be charged with a high current (2 amperes) using the included 10 W USB power adapter. While it can be charged by a standard USB port from a computer, these are limited to 500 milliamperes (half an amp). As a result, if the iPad is turned on while connected to a normal USB computer port, it may charge much more slowly, or not at all. High-power USB ports found in newer Apple computers and accessories provide full charging capabilities.
The iPad 2 battery is 2.5 mm thick, 59% smaller than the original and has three cells instead of two, allowing the injection-molded plastic support frame to be omitted.
Apple claims that the battery for both generations of iPad can provide up to 10 hours of video, 140 hours of audio playback, or one month on standby. Like any battery technology, the iPad's LiPo battery loses capacity over time, but is not designed to be user-replaceable. In a program similar to the battery-replacement program for the iPod and the original iPhone, Apple will replace an iPad that does not hold an electrical charge with a refurbished iPad for a fee of $99 (plus $6.95 shipping).
Storage and SIM
The iPad was released with three capacity options for storage: 16, 32, or 64 GB of internal flash memory. All data is stored on the internal flash memory, with no option to expand storage. Apple sells a camera connection kit with an SD card reader, but it can only be used to transfer photos and videos.
The side of the Wi-Fi + 3G model has a micro-SIM slot (not mini-SIM). Unlike the iPhone, which is usually sold locked to specific carriers, the 3G iPad is sold unlocked and can be used with any compatible GSM carrier. Japan is the exception to this, where the iPad 3G is locked to Softbank. In the U.S., data network access via T-Mobile's network is limited to slower EDGE cellular speeds because T-Mobile's 3G Network uses different frequencies. The iPad 2 introducd a third tier of models with CDMA support for Verizon Wireless in the United States, available separately from the AT&T capable version
Like iPhone and iPod Touch, the iPad is controlled by a multitouch display—a departure from most previous tablet computers, which used a pressure-triggered stylus—as well as a virtual onscreen keyboard in lieu of a physical keyboard. The iPad uses a Wi-Fi data connection to browse the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to HSPA or EV-DO data networks. The device is managed and synced by iTunes on a personal computer via USB cable.
Apple released the first iPad in April 2010, and sold 3 million of the devices in 80 days. During 2010, Apple sold 14.8 million iPads worldwide, representing 75 percent of tablet PC sales at the end of 2010. By the release of the iPad 2 in March 2011, more than 15 million iPads had been sold— more than all other tablet PCs combined. In 2011, it is expected to take 83 percent of the tablet computing market share in the United States
The iPad's touchscreen display is a 9.7 in (25 cm) liquid crystal display (1024 × 768 pixels) with fingerprint-resistant and scratch-resistant glass. Steve Jobs backed the choice of screen size, saying a 7-inch screen would be "too small to express the software." He said 10 inches was the minimum for a tablet screen. Like the iPhone, the iPad is designed to be controlled by bare fingers; normal gloves and styli that prevent electrical conductivity may not be used, although there are special gloves and capacitive styli designed for this use.
The display responds to other sensors: an ambient light sensor to adjust screen brightness and a 3-axis accelerometer to sense iPad orientation and switch between portrait and landscape modes. Unlike the iPhone and iPod touch built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad built-in applications support screen rotation in all four orientations, including upside-down. Consequently, the device has no intrinsic "native" orientation; only the relative position of the home button changes. The iPad 2 added a 3-axis gyroscope that is used only third party apps, usually games.
There are four physical switches on the iPad, including a home button near the display that returns the user to the main menu, and three plastic physical switches on the sides: wake/sleep and volume up/down, plus a third which, whose function has changed with software updates. Originally, the switch would lock the screen to its current orientation, but the iOS 4.2 changed it to a mute switch, with rotation lock now available in an onscreen menu. In the iOS 4.3 update, released with the iPad 2, a setting was added to allow the user to specify whether the side switch was used for rotation lock or mute.
Apple reduced the size of the iPad 2 by 33% compared to its predecessor by eliminating the stamped sheet metal frame from the display, integrating new thinner glass technology for the touch screen overlay, and slightly reducing the space between the display and battery. The iPad 2's screen is thinner, lighter, and yet stronger than the original iPad's.
The original iPad had no camera. The iPad 2 has front VGA camera and a rear-facing 720p camera, both capable of still images and 30fps video. The rear facing camera has a 5x digital zoom for still images only. Both shoot photo and video in a 4:3 fullscreen aspect ratio, unlike the iPhone 4, which shoots in a 16:9 widescreen aspect ratio. It also lacks the iPhone's tap to focus feature. The cameras allow FaceTime video messaging with iPhone 4, iPod Touch 4, and Snow Leopard Macs
ConnectivityThe iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Maps. The 3G model contains A-GPS to allow its position to be calculated with GPS or relative to nearby cellphone towers; it also has a black plastic accent on the back side to improve 3G radio sensitivity.
For wired connectivity, the iPad has only a TRRS headphone jack and a proprietary Apple dock connector; it lacks the Ethernet and USB ports of larger computers.
Audio and outputthe iPad has two internal mono speakers located on the bottom-right of the unit. In the original iPad, the speakers push sound through two small sealed channels leading to the three audio ports carved into the device, while the iPad 2 has its speakers behind a single grill.
A volume switch is on the right side of the unit. A 3.5-mm TRRS connector audio-out jack on the top-left corner of the device provides stereo sound for headphones with or without microphones and/or volume controls. The iPad also contains a microphone that can be used for voice recording.
The built-in Bluetooth 2.1 + EDR interface allows wireless headphones and keyboards to be used with the iPad. However, the iOS does not currently support file transfer via Bluetooth. iPad also features 1024 x 768 VGA video output for limited applications, screen capture, connecting an external display or television through an accessory adapter.
Power and batteryThe iPad uses an internal rechargeable lithium-ion polymer battery (LiPo). The batteries are made in Taiwan by Simplo Technology, which makes 60% of them, and Dynapack International Technology. The iPad is designed to be charged with a high current (2 amperes) using the included 10 W USB power adapter. While it can be charged by a standard USB port from a computer, these are limited to 500 milliamperes (half an amp). As a result, if the iPad is turned on while connected to a normal USB computer port, it may charge much more slowly, or not at all. High-power USB ports found in newer Apple computers and accessories provide full charging capabilities.
The iPad 2 battery is 2.5 mm thick, 59% smaller than the original and has three cells instead of two, allowing the injection-molded plastic support frame to be omitted.
Apple claims that the battery for both generations of iPad can provide up to 10 hours of video, 140 hours of audio playback, or one month on standby. Like any battery technology, the iPad's LiPo battery loses capacity over time, but is not designed to be user-replaceable. In a program similar to the battery-replacement program for the iPod and the original iPhone, Apple will replace an iPad that does not hold an electrical charge with a refurbished iPad for a fee of $99 (plus $6.95 shipping).
Storage and SIM
The iPad was released with three capacity options for storage: 16, 32, or 64 GB of internal flash memory. All data is stored on the internal flash memory, with no option to expand storage. Apple sells a camera connection kit with an SD card reader, but it can only be used to transfer photos and videos.
The side of the Wi-Fi + 3G model has a micro-SIM slot (not mini-SIM). Unlike the iPhone, which is usually sold locked to specific carriers, the 3G iPad is sold unlocked and can be used with any compatible GSM carrier. Japan is the exception to this, where the iPad 3G is locked to Softbank. In the U.S., data network access via T-Mobile's network is limited to slower EDGE cellular speeds because T-Mobile's 3G Network uses different frequencies. The iPad 2 introducd a third tier of models with CDMA support for Verizon Wireless in the United States, available separately from the AT&T capable version
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