Screen and input
The iPad's (first two generations) touchscreen display is a 1,024 by 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 said a 7-inch screen would be
"too small to express the software" and that 10 inches was the minimum
for a tablet screen. Like the iPhone, the iPad is designed to be controlled by bare fingers; normal, non-conductive gloves and styli do not work, 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'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. 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.
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.
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 (but these are only taken at a low quality 0.3 megapixels) and 30fps video. The rear-facing camera has a 5× 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. The cameras allow FaceTime video messaging with iPhone 4, iPod Touch 4, and Snow Leopard, Lion, and Mountain Lion Macs.
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..The iPad has a headphone jack and a proprietary Apple dock connector, but no Ethernet or USB port.
However, the Apple Camera Connection Kit accessory provides two dock
connector adapters for importing photos and videos via USB and SD memory
cards.
Audio and output
The iPad has two internal speakers reproducing left and right channel
audio 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 iOS does not currently support file transfer via Bluetooth. iPad also features 1024×768 VGA video output for limited applications, screen capture, connecting an external display or television through an accessory adapter.
Power and battery
The iPad uses an internal rechargeable lithium-ion polymer (LiPo) battery. The batteries are made in Taiwan by Simplo Technology (60%) and Dynapack International Technology.
The iPad is designed to be charged with a high current of 2 amperes
using the included 10 W USB power adapter and USB cord with a USB
connector at one end and a 30-pin dock connector at the other end. 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.
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 rechargeable battery technology, the iPad's
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 US$99 plus
$6.95 shipping. As a different unit is supplied, user data is not preserved. The refurbished unit will have a new case. The warranty on the refurbished unit may vary between jurisdictions.
Independent companies also provide a battery replacement service,
returning the original unit with new battery but original case.
Alternatively it is possible for a technically competent user to buy and
install a new battery, which may invalidate any remaining warranty on
the iPad. The task does not require soldering, but is technically
challenging.
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). The 3G iPad can be used with any compatible GSM carrier, unlike the iPhone, which is usually sold 'locked' to specific carriers. 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 introduced a third tier of models with CDMA support for Verizon Wireless in the United States, available separately from the AT&T capable version.
Optional accessories
Main article: iPad accessories
Apple offers several iPad accessories, most of which are adapters for the proprietary 30-pin dock connector, the iPad's only port besides the headphone jack.
A dock holds the iPad upright at an angle, and has a dock connector and
audio line out port. Each generation of iPad requires a corresponding
dock. A dock that included a physical keyboard was only supported for
the original iPad, but all generations are compatible with Bluetooth keyboards that also work with Macs and PCs.
The iPad can be charged by a standalone power adapter ("wall charger")
also used for iPods and iPhones, and a 10 W charger is included with the
iPad.
Apple sells a camera connection kit that consists of two separate adapters for the dock connector, one to USB Type A, the other an SD card reader. Adapter can be used to transfer photos and videos and to plug USB audio card or MIDI keyboard. A third party sells an adapter that includes USB, SD, and microSD on a single unit.An adapter to VGA connectors allows the iPad to work with external monitors and projectors. Another adapter mirrors the screen onto HDMI
compatible devices in 1080p and works with all apps and rotations.
Unlike other adapters, it allows the iPad to charge through another dock
connector. While the HDMI adapter was released with and advertised for the iPad 2, it also works with the first-generation iPad, the iPhone 4, and the fourth generation iPod Touch.
Smart Covers are screen protectors that magnetically attach and align
to the face of the iPad 2. The cover has three folds which allow it to
convert into a stand, which is also held together by magnets.
While original iPad owners could purchase a black case that included a
similarly folding cover, the Smart Cover is meant to be more minimal,
easily detachable, and protects only the screen. Smart Covers have a microfiber
bottom that cleans the front of the iPad, which wakes up when the cover
is removed. There are five different colors of both polyurethane and
leather, with leather being more expensive. Smart Covers are not
compatible with the original iPad.
In June 2012, Apple started selling the Smart Case - a case with the
combined function of a smart cover and a back protection case which is
compatible with the second and third generation iPads.
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