Page 570 - Ultimate Visual Dictionary (DK)

THE MODERN WORLD
Handheld computer Sleep/wake button

BY THE EARLY 1990s electronic circuitry had
been miniaturized to such an extent that it was
possible to make small handheld computing devices.
The first of these was the Personal Digital Assistant
(PDA), which offered features including an address
book, calendar, and notepad. In recent years, PDAs
have been overtaken by smartphones with internet and
email access (see pp. 588–589). A related product is the
e-book reader, which stores books in digital form and
uses “electronic paper” to mimic the appearance of ink
on real paper. An e-book reader no bigger than a thin
paperback can store several thousand digital books in
its memory. The most recent small computing device is
the handheld computer. This looks like a thin flat
display, but it is actually a complete computer.
Handheld computers are typically controlled by a
touch-sensitive screen and have a wireless link to other
computers and the internet. They run software
applications, or apps, downloaded from the internet.
The most popular handheld computer currently is the
Apple iPad. It has a multitouch interface that enables
its screen to detect the movements of fingertips. In
addition to selecting options and apps by touching the
screen, images can be enlarged or shrunk by moving
fingertips apart or together on the screen.

Touch data is sent
as a list of finger LCD with buttons
positions to the displayed APPLE IPAD Home button App icon
controller where
the information is
used to zoom in Fingers alter the electric
and out of a field around nearby
web page
sections of the grid
User touches clear
protective screen

6-in (15-cm)
screen
Touchscreeen
electronics Next page
interpret the button
outputs from the Joystick
grid to work out Previous controller
Controller exactly where page button
the fingers are
MULTITOUCH INTERFACE ACER LUMIREAD E-READER

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