Write short notes on :-
(i)Digtal camera (ii) Scanner (iii) Touch screen; (iv) Magnetic
Ink Character Recognition (MICR)
Subject | Introduction to Computer System |
---|---|
NU Year | Set: 3.(b) Marks: 10 Year: 2012 |
Digital camera
A digital camera
records and stores photographic images in digital form. Many current models are
also able to capture sound or video, in addition to still images. Capture is
usually accomplished by use of a photo sensor, using a charged coupled
device (CCD). These stored images can be uploaded to a computer immediately or
stored in the camera for to be uploaded into a computer or printer later.
Images may also be archived on a photographic compact disc or external hard
disk.
Scanner
A scanner is a device
that captures images from photographic prints, posters, magazine pages, and
similar sources for computer editing and display. Scanners come in hand-held,
feed-in, and flatbed types and for scanning black-and-white only, or color.
Very high resolution scanners are used for scanning for high-resolution
printing, but lower resolution scanners are adequate for capturing images for
computer display. Scanners usually come with software, such as Adobe's Photoshop
product, that lets you resize and otherwise modify a captured image.
Touch screen
A touch screen is a
computer display screen that is also an input device. The screens are sensitive
to pressure; a user interacts with the computer by touching pictures or words
on the screen.
There are three types
of touch screen technology:
Resistive: A
resistive touch screen panel is coated with a thin metallic electrically
conductive and resistive layer that causes a change in the electrical current
which is registered as a touch event and sent to the controller for processing.
Resistive touch screen panels are generally more affordable but offer only 75%
clarity and the layer can be damaged by sharp objects. Resistive touch screen
panels are not affected by outside elements such as dust or water.
Surface wave: Surface
wave technology uses ultrasonic waves that pass over the touch screen panel.
When the panel is touched, a portion of the wave is absorbed. This change in
the ultrasonic waves registers the position of the touch event and sends this
information to the controller for processing. Surface wave touch screen panels
are the most advanced of the three types, but they can be damaged by outside
elements.
Capacitive: A
capacitive touch screen panel is coated with a material that stores electrical
charges. When the panel is touched, a small amount of charge is drawn to the
point of contact. Circuits located at each corner of the panel measure the
charge and send the information to the controller for processing. Capacitive
touch screen panels must be touched with a finger unlike resistive and surface
wave panels that can use fingers and stylus. Capacitive touch screens are
not affected by outside elements and have high clarity.
Magnetic
Ink Character Recognition
Magnetic Ink Character Recognition
is a character recognition system that uses special ink and characters. When a
document that contains this ink needs to be read, it passes through a machine,
which magnetizes the ink and then translates the magnetic information into
characters.
MICR technology is used
by banks. Numbers and characters found on the bottom of checks (usually
containing the check number, sort number, and account number) are printed using
Magnetic Ink. To print Magnetic Ink need, you need a laser printer that accepts
MICR toner.
MICR provides a secure,
high-speed method of scanning and processing information.