The iPad 2 has been available for purchase, depending on stock availability, since March 11, 2011, at Apple retail stores in the United States, as well as to United States customers shopping online at Apple's retail website.[53] The iPad 2 was released internationally in 25 other countries on March 25, 2011, including Australia, Canada, France, Germany, Mexico and the United Kingdom, but not Japan as originally scheduled due to the earthquake and tsunami.[54]
[edit]Hardware
[edit]Screen and input
The iPad's touchscreen display is a 1024 × 768 pixel, 7.75×5.82 in (197×148 mm) liquid crystal display (diagonal 9.7 in (246.4 mm)), with fingerprint- 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" and that 10 inches was the minimum for a tablet screen.[55] Like the iPhone, the iPad is designed to be controlled by bare fingers; normal, non-conductive gloves and styli do not work,[56]although there are special gloves and capacitive styli designed for this use.[57][58]
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's built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad's built-in applications support screen rotation in all four orientations, including upside-down.[59] Consequently, the device has no intrinsic "native" orientation; only the relative position of the home button changes.
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 software-controlled switch whose function has changed with software updates. Originally the switch locked 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.[60] 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.[13]
The original iPad had no camera; the iPad 2 has a front VGA camera and a rear-facing 720p camera, both capable of still images and 30fpsvideo. 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. Unlike the iPhone, the iPad does not support tap to focus, but does allow you to tap to set auto exposure.[61] The cameras allow FaceTime video messaging with iPhone 4, iPod Touch 4, and Snow Leopard/LionMacs.[62]
[edit]Connectivity
The iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Maps. The 3G model supports A-GPS to allow its position to be calculated with GPS or relative to nearby cellphone towers; it also has a black strip on the back to aid 3G reception.[63]
The iPad has a headphone jack and a proprietary Apple dock connector, but no Ethernet or USB port.[13] However, the Apple Camera Connection Kit accessory provides two dock connector adapters for importing photos and videos via USB and SD memory cards.
[edit]Audio and output
The 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,[17] while the iPad 2 has its speakers behind a single grill.[16]
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.[64] However, the iOS does not currently support file transfer via Bluetooth.[65] iPad also features 1024 x 768 VGA video output for limited applications,[66] screen capture,[67] connecting an external display or television through an accessory adapter.
[edit]Power and battery
The iPad uses an internal rechargeable lithium-ion polymer (LiPo) battery. The batteries are made in Taiwan by Simplo Technology (60%) andDynapack International Technology.[68] The iPad is designed to be charged with a high current of 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 (0.5 amps). As a result, if the iPad is running while powered by a normal USB computer port, it may charge very slowly, or not at all. High-power USB ports found in newer Apple computers and accessories provide full charging capabilities.[69]
Apple claims that the battery for both generations of iPad can provide up to 10 hours of v
Click Adds to see more
http://en.wikipedia.org/wiki/IPad
