Page 64 - Computer - 9(A&B)

Touch Screen

A touch screen is a display device which gives input to a computer by responding to touch
input. We use our fi nger to point directly to objects on responding to touch improve rather
than using a mouse or a keyboard. Some monitors are provided with a screen that is
sensitive to touch. When a user touches the screen to make a choice, the grid determines
the location of the touch. The data is then passed on to the processor. These screens are
used at airlines and railways reservation counters. The destination and source of fl ights or
trains are displayed on the screen. It is commonly used on cellphones, PDAs, ATM
machines, video games and even super market terminals.

Touchpad

This has a special surface which can sense the movement of fi nger. It is used to move the
pointer by moving the fi ngers on the pad. This is mainly found in laptop computers.

Graphic Tablet

Graphic tablet is an input device that fi nds its application in CAD (Computer Aided
Designing). It consists of a grid of copper wires embedded on a fl at surface. This grid is
connected to the processor. A pen-like device called stylus is attached to the grid. When
the stylus moves over the grid, the wire mesh of the tablet senses the position of stylus as
it moves. These coordinates are transmitted to the processor. The signals are interpreted
and accordingly an image is displayed on the monitor.

Smart Card Reader

A smart card contains a microprocessor that holds certain information
like PIN number, account number, etc. Smart card readers are special
machines where these cards are put in. The information contained
in them is read and verifi ed with the information stored inside the
computer system. They are basically an extension of ATMs (Automated
Teller Machines). They are commonly used in banking.

Biometric Sensor

This is the latest technology in the fi eld of input devices. Biometrics is the measuring of
unique attributes of a human such as DNA matching, fi ngerprints identifi cation, face
shape comparisons, etc. Biometric sensors accept data such as fi ngerprints, face shape
or voice of the user as input. The data is then matched with the data already stored in
the memory of the computer. If a match is found, further action is taken. In the future,
these devices may replace your credit cards, smart cards, etc. In a biometric sensor
device, you will place your fi nger in the scanner area. If the pattern of your fi nger matches with the attributes
stored in the memory, you will be allowed to withdraw cash or carry out any other transaction.

Optical Mark Reader (OMR)

The optical mark reader can recognise a mark made by a pen or a pencil. OMR sheet is used for answering
multiple choice type questions in various competitive exams. It has a layout as shown in the fi gure.

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