INPUT DEVICE

Scanner
There are two types of Scanner

1. 2D Scanner
2. 3D Scanner

2D Scanner
2D Scanner converts a Hard copy document into an electronic form to be stored as a file on a computer

Operations Of 2D Scanner
1. 2D Scanner shines a light onto the surface of a documents which means that light moves across
document
2. Reflected light is captured
3. Uses mirrors and lenses
4. Captured image is converted into a digital file
5. Produces a 2D digital image

Application of 2D Scanner
1. 2D Scanners are used in airports to read people’s passport.
2. OCR software can be used to change or copy text in an electronic form of the scanned passport.
3. The photo in the passport is also is scanned and is stored as a .jpeg file. A photo of the
passenger’s face is also taken at the airport and compared with the image in the passport.

Optical Character Recognition (OCR)

 Computer with Optical Character Recognition (OCR) software allow scanned text to be
converted into a text file format
 Now the scanned image can be changed by importing into a word processor
 If the document was an image file is formed
3D Scanner
A 3D Scanners scans a solid object and produces a 3D image of it.

Operations Of 3D Scanner
1. 3D Scanners shines a laser (or light) over the surface of a 3D object.
2. Records measurements of the geometry / dimensions of the object.
3. Measurements are converted to digital file
4. Produces a 3D digital model

Application of 3D Scanners Computed Tomography (CT)

COMPUTED TOMOGRAPHIC (CT) SCANNERS are used to create a 3D image of a solid object. This is based
on TOMOGRAPHY technology which basically builds up an image of the solid object through a series of
very thin 'slices'. Together these 2D 'slices' make up a representation of the 3D solid object.

RAYS TYPE OF SCANNER

X-rays CT (Computerised Tomography)
Radio waves MRI (Magnetic Resonance imaging)
Gamma rays SPECT(Single Photo emission computed topography)
Barcode Reader
Barcode is a series of black and white parallel line of different thickness, barcode can hold upto 30 digit.

Application Of Barcode Reader

1. Supermarket Checkout
 Read barcode to find price, description
 Always automatic stock control

2. Library System
 Can track book on loan
 Can link books to browser using barcode cards

3. Airport Check – ins

 Barcode on language to track whereabouts

How does a barcode work?

 Barcode is read by a red laser.
 The light hit the series and is reflected back
 Reflected lights is read by the sensor
 A pattern is generated which is converted into a digital data

How the Barcode System could help the supermarket manage it’s stock
 Barcode identifies a unique product
 Barcode can be used to look up product (in a database)
 Data about stock levels can be stored on a system
 Stock can be automatically deducted from the system
 Can check stock is below a certain level / check stock level
 Automatic re-order / Alerts when stock is low automatically update new stock level
  To locate if an item of stock is available in another location

Advantages to the management of using barcodes

 much easier and faster to change prices on stock items
 much better, more up-to-date sales information/sales trends
 no need to price every stock item on the shelves (this reduces time and cost to the
management)
 allows for automatic stock control
 possible to check customer buying habits more easily by linking barcodes to, for example,
customer loyalty cards

Advantages to the customers of using barcodes

 faster checkout queues (staff don't need to remember/look up prices of items)
 errors in charging customers is reduced » the customer is given an item bill
 cost savings can be passed on to the customer
 better track of 'sell by dates' so food should be fresher

Quick Response (QR) code

QR Code is a Type of barcode. A Quick Response (QR) code is made of black squares on a white
background.

Barcode QR Code
30 digit 7000 digit
Old form of Barcode Modern form of Barcode
Black and white series of parallel lines of different Series of black and white matrix
thickness
Barcode Reader Cellphone / App
Less data store More data store
Supermarket Advertisement on product
Advantages of QR Code
 It is not necessary for the user to type the URL, the only need to scan a QR code with an app and
they will be directed to the website
 QR code can displayed in train, buses, magazines or bus cards given an effect way of advertising.

How Data Is Stored In The QR Code Is Read (Scan)

1. Read/Scanned using app (on mobile device)
2. The three large squares are used to define the alignment / uses alignment targets / modules
3. It is the camera that is used to scan / capture the image
4. Black squares reflect less light / white squares reflect more lights
5. The app / device processes the image
6. Each small square / pixel is converted to a binary

Digital Cameras
A digital camera is a camera which can be produce digital image that can be stored in a computer.

A Digital Camera Is Controlled By A Microprocessor, Which Can

 Automatically focus on the image
 Automatically operates the flash
 Adjust shutter speed
 Adjust the aperture size
 Adjust the size of the image
 Remove “Red eye”
How the captured images are converted to digital photo file
 Image is converted Analogue to digital (Using ADC)
 Image is turned into pixel
 Each pixel is given a binary value
 Pixel form a grid (to create the image)
 Each pixel has a colour
 Pixel are stored in a sequence
 Meta data is stored (to describe the dimensions / resolution of the image)
 An example of a suitable photo file format e.g. JPEG

Keyboard

Keyboards are by far the most common method used for data entry. They are used as the input devices
on computers, tablets, mobile phones and many other electronic items. The keyboard is connected to
the computer either by using a USB connection or by wireless connection. In the case of tablets and
mobile phones, the keyboard is often virtual or a type of touch screen technology.

Internal Operation Of Keyboard

 Uses switches and circuits to translate keystrokes into signals the computer can understand
 The key matrix is a grid of circuits / three layer of plastic underneath the keys
 Each circuit is broken beneath the key / middle layers contain holes
 When key pressed, a circuit is completed and a signal is sent
 Processor compares location of signals from key matrix to character map stored on ROM
 A character code for each key press is stored in a keyboard buffer

Touchscreen
Touchscreens are now a very common form of input device. They allow simple touch to launch an
application or to carry out many of the functions of pointing devices such as a mouse.

One of the main uses of touchscreen technology is in mobile phones. At present, there are three major
types of touchscreen technologies applied to mobile phone screens:

1. Capacitive
2. Infra-red
3. Resistive
Capacitive

 Capacitive is made of many layers of glass that acts like a capacitor creating electric fields
between the glass plates.
 When the top glass is touched the electric current changes and the coordinates where the
screen is touched is determined by an on-board microprocessor

Advantages
 Medium cost technology
 Screen visibility in strong sunlight
 It permits multi-touch capabilities
 Durability

Disadvantages
 Allows only bare finger Use

Infra-Red
Infrared touch screens use a glass screen with an array of sensors and infrared transmitters

Advantages Compared To The Other Two Technologies

 Allows multi-touch facilities
 Has good screen durability
 The operability isn't affected by a scratched or cracked screen.
Disadvantages Compared To The Other Two Technologies
 The screen can be sensitive to water or moisture
 It is possible for accidental activation to take place if the infrared beams are disturbed in some
way
 Sometimes sensitive to light interference

Resistive

 This makes use of an upper layer of polyester (Plastic) and a bottom layer of glass
 When the top bottom layer is touched, the top layer and bottom layer complete the circuit.

Advantages
 It is a cheap technology
 It is possible to use bare fingers, gloved fingers or a stylus to carry out an input operation.

Disadvantages
 Screen visibility is poor in strong sunlight
 It does not permit multi touch capabilities
 The screen durability is only fair, it is vulnerable to scratches

Application Of Touchscreen
1. Ticket / Information Desk
 Easy method for public to enter data
 Limited no of options
2. Mobile Phone / Tablet
 Easy method to input data
 Use of icons for application
3. Control Room Interface
 Faster / easier method to input data into system
 Fewer chances of error since no of choice limited
Microphones
A microphone is a device which can input sound into a device. Microphone converts sound into an
electrical signal/voltage.

Microphones can be used for

 Doing a voice over in a presentation
 Speech recognition
 Voice recognition
 Enabling disabled people to communicate with computers
 When a microphone detects sound, a diaphragm vibrates producing an electrical signal
 This signal is transmitted to a sound card and is converted into a digital data and is then stored
in a computer

Basic Internal Operations Of Microphones

1. The Microphone has a diaphragm
2. The incoming sound waves cause vibration
3. Vibration causing a coil to move past a magnet (In dynamic microphones)

Types Of Microphones
There are two types of microphones

1. Condenser Microphones
 Change in capacitance
2. Dynamic Microphones
 Change in current
Sensor
Sensors are devices which read/measure the physical properties.

 Physical data is known as analogue. This means that it is constantly changing and
doesn’t have a discrete value
 Analogue data requires some way to interpret. For example, a mercury
thermometer requires you to look at the height of mercury
 Temperature can be therefore have an infinite number of values
 As humans, we can read these values. However a computer cannot. The data needs
to be converted into a digital format
 This is done by using an Analogue to Digital Converter (ADC). This Device converts
physical analogue values into discrete digital values.

Analogue Data ADC Digital Data

 When Computer or microprocessor are used to control devices, it is necessary

to use a Digital to analogue converter.
 These are used in actuators, which is a type of electromechanical output device
used to control something.
 Actuators may require a DAC to receive an electrical current rather than a digital
signal

Digital Data DAC Analogue Data

 Sensor Application

Temperature  Controlling a central heating system

 Controlling/monitoring a chemical process
 Controlling/monitoring the temperature in a greenhouse
Moisture/Humidity  Controlling/monitoring the moisture levels of the soil in a greenhouse
 Controlling/monitoring the humidity levels of the air in a greenhouse
 Monitoring the dampness in an industrial application
Light  Controlling Street lights
 Controlling/monitoring lights in a greenhouse
 Controlling headlights in a car
Infra-red/Motion  Controlling the windscreen wipers in a car
 Monitoring intruders in a burglar alarm system
 Controlling doors in a shopping mall
Pressure  Monitoring intruders in a burglar alarm system
 Controlling a weighing system
 Controlling/monitoring a gas pressure-related process
Sound  Monitoring intruders in a burglar alarm system
 Monitoring the noise of liquid dripping from a pipe
Gas  Monitoring pollution in water or the air
 Monitoring the O2 and CO2 gas in a greenhouse
 Monitoring CO2 leaks in a power station
pH (Power of  Controlling/monitoring acidity/alkalinity of soil in a greenhouse
Hydrogen)  Monitoring pollution in water
Magnetic Field  Controlling an application which involves magnetic field changes
 Controlling an alti-lock breaking system in cars
Working Of Sensor
Sensors send signals to a microprocessor/
computer

The signals are converted into digital (If

required) using an ADC

The microprocessor/computer checks the

data received against stored values

Monitoring System Controlling System

If the received data is outside a set range

A warning message/alarm The computer /

is Output microprocessor sends
signals to control actuators

Interactive Whiteboards
An interactive whiteboard is a device which can display images on a whiteboard using a projector.
Interactive whiteboard allows a user to write on a surface using pen; text and drawings are then
captured electronically and stored for later use.
  They allow user to write or drawn on it. These writings and drawings are then stored in an
electrical form to be used for later.
 This can be helpful in meetings and classes in school.
 For example, a plant cell is displayed on the whiteboard in a biology lesson.
 It is possible to student to label the parts of the cell on the whiteboards and have the
annotations saved on the computer for the next lesson.
 It is also possible to interact with them using our fingers on the surface.
 Doing this, people can do on the whiteboards what they can do on the computer (such as
browsing the internet or paying a game)
 Since a white is used, many people can watch and involved.

Optical Mouse
An optical mouse is an example of a pointing device. It uses tiny cameras to take 1500 images per
second. Unlike an older mechanical mouse, the optical mouse can work on virtually any surface. A red
LED is used in the base of the mouse and the red light is bounced off the surface and the reflection is
picked up by a complementary metal oxide semiconductor (CMOS). The CMOS generates electric pulses
to represent the reflected red light and these pulses are sent to a digital signal processor (DSP). The
processor can now work out the coordinates of the mouse based on the changing image patterns as it is
moved about on the surface. The computer can then move the on-screen cursor to the coordinates sent
by the mouse.

Benefits Of An Optical Mouse Over A Mechanical Mouse

 There are no moving parts, therefore it is more reliable.
 Dirt can’t get trapped in any of the mechanical components.
 There is no need to have any special surfaces.
OUTPUT DEVICES
Inkjet Printer
A printer in which the character/images are formed by minute jets of ink. Inkjet printer uses liquid ink
to generate a physical output.

Four Components Of Inkjet Printer

 A paper head consisting of nozzles which spray ink droplets on paper to form character/image.
 Ink cartridge (usually two: one black and one blue, yellow and magenta)
 A stepper motor and belt which moves the print head across the paper.
 A paper feed which feeds the printer with printer.

Ink Droplets Technology #1 “Thermal Bubble”

 Tiny resistors, create heat, making the ink vaporize
 The ink forms a tiny bubble which extends, causing some on the ink to land on the paper
from the print head
 The bubbles collapses and a small vacuum is created, allowing new ink to be drawn into the
print head
 This continues until the print job is complete

Ink Droplets Technology #2 “Piezoelectric”

 A crystal, located at the back of the ink supplying for each nozzle, is given a tiny electric
charge, causing it to vibrate.
 The vibration cause ink to land on the paper from print head.
 Meanwhile, more ink is drawn in for the next print
Basic Steps In The Printing Process Of Inkjet Printer

1.The data from the 2.The printer driver 3. The printer driver
file to be printed is checks that the data is checks if the printer is
sent to printer in an understandable able to carry out the
driver format print job

6. The printer head 5. A piece of paper is 4. The data is sent to

moves across the fed into the printer. If the printer and is
paper to produce an error occurs, a stored in a printer
the character/ image message is sent to the buffer
computer

7. At the end of each 8. The process from 9. The printer buffer

pass of the print head step 5 is repeated until sends an interrupt to
the paper is advanced the printer buffer is the computer
slightly to print the empty requesting mor data to
next line be sent

Application / Use Of Inkjet Printer

 Photographs: They are best for printing good quality one off photos
 Time is because of the small size of ink cartridge and paper trays, so there would be no issue
 Small quantities of document

Laser Printer
A printer that uses a static electric charge on a rotating drum to generate a physical output.

 Laser printer use dry powder ink instead of liquid ink to print
  They also use static electricity to print characters and images
 Unlike inkjet printers, which print line by line, laser printers print the whole page in one go
 This gave them a speed advantage, which is why they are suitable for large prints jobs
 They also don’t run out of ink halfway like inkjet printers do

Description Of Laser Printer

 Uses toner / powder ink
 Uses (Positive and negative) charged drums/rotating drums
 Uses static charge
 No moving head
 Faster at printing
 High volume output/ high speed
 Producing flayers/leaflets/magazines

9 Stages That Occur When A Document Is Printed Using A Laser Printer

2. The printer 3. The printer 4. The data is sent to
1. The data from
driver checks that driver checks if the the printer and is
the file to be
the data is in an printer is able to stored in a printer
printed is sent to
understandable carry out the print buffer
a printer driver.
format. job.

5. A printing drum in the printer is given a positive

6. The drum is then covered with positively
charge. A laser beam removes positive charge in
charged toner (powdered ink) which sticks to
certain areas. This leaves negatively charged areas,
the negatively charged areas of the drum.
which match the characters/images to be printed.

7. A negatively charged 8. The negative charge is 9. The paper goes through a fuse,
piece of paper is rolled removed from the paper which melts the ink onto the
over the drum, causing the to prevent it from sticking paper. A discharge lamp removes
toner to stick to the paper. to the drum. all the charge from the drum,
preparing it for the next job.
Application / Use of Laser Printer
 As mentioned, laser printer have speed advantage over inkjet printer
 Therefore laser printers are good for large, high-quality quality print jobs; high volume printing
 For example: printing many flayers or posters to put around the town.
 Another reason for this besides speed is they have large toner cartridge and large print trays.

3D Printers
A printer which makes a physical object from a 3D digital model (usually used in CAD).

3D Printers Use 5 Various Ways To Produce Solid Objects

1 Additive Manufacturing
 One type of manufacturing 3D printer use in additive manufacturing
 The 3D object being printed is build up layer-by-layer using powdered resin, powdered
metal and ceramic powdered or paper
2 Subtractive Manufacturing
 The 3D object being printed is carved from a block of stone until the object
3 Direct Printing
 This uses inkjet technologies: a print head move side-by-side like an inkjet printer, but
can also move up and down to build the layer
4 Binder Printing
 The print head moves like in direct 3D printing, but two substances are sprayed for each
layer dry powder and binder to form the object
5 Use of UV light
 Other technologies make use of UV light to harden liquid polymer, which increase the
diversity of products that can be produced
Steps In The Process Of Producing An Object Using These 3D Printers
A design is made The finalized drawing is imported The 3D printer is first set up to
using computer aided into some special software that allow the solid object to be
design (CAD) prepares it in a format that is made
software understood by the 3D printer

The object is removed from the printer and is then The solid object is built up layer by
prepared; for example, some use a jelly-like support that layer (often only 0.1 mm thick);
needs to be washed away by immersion in water, some this can take several hours
require the removal of excess plastic powder and others depending on the thickness of the
require the cutting away of unused material; in many layers, the material used and the
cases, the object has to be left to ‘cure’ for a few hours. size of the final object

Application / Use Of 3D Printers

 the covering of prosthetic limbs can be made to exactly fit the limb
 fashion and art – 3D printing allows new creative ideas to be developed
 making parts for items no longer in production e.g. suspension parts for a vintage car.

2D Cutter
2D cutter uses a high power laser to generate a physical output. High power laser that use the x-y plane
to cut.

3D Cutter
A three dimensional (3D) laser cutter works in a similar way to a two-dimensional (2D) cutter.

The Main Difference Is That The 3D Cutter Can Recognize

An Object In The x, y, z Direction Rather Than Just x, y
 A laser cutter is a device which can cut materials.
 A laser cutter can cut material such as glass, polymer, metal, crystal and wood.
 A 2D laser cutter cuts in the x-y direction, while a 3D cutter can cuts in the x-y-z direction.
 The laser 3D cutter can controlled by computers and software CAD which means that complex
and cool designs can easily be made.
Actuator
An actuator is an electromechanical device used to operate or control something.

 An actuator (Such as motor, relay or solenoid) is used in controlling application

 When energized, an actuator can operate or control a system (for example, a solenoid could be
used to operate a plunger or control a fuel injection system)
 A DAC is sometimes required to control an actuator. A computer is connected with the actuator
and data sent to it will go through the DAC when being transmitted to the actuator.

Loud Speaker
Sound is produced from a computer by transmitting digital values through a DAC and then through an
amplifier and finally to the speaker where it is output.

A Device Which Converts Electrical Impulses Into Sound

Sound is produced from a computer by passing the digital data through a DIGITAL TO ANALOGUE
CONVERTER (DAC) and then through an amplifier; finally the sound emerges from a (loud) Speaker. The
sound is produced by voltage differences vibrating a cone in the speaker housing at different
frequencies and amplitude.

Digital Analogue Amplified

Computer Data DAC Data Data

Amplifier Speaker
Projector
A device that displays a computer output onto a wall, large screen or interactive whiteboard

Digital Light Projector (DLP)

DLP Uses millions of micro mirrors to reflect light through a lens

DLP relies on millions of micro mirrors which can switch on or several thousand times a second creating
various shades of grey. Colour filters allow the shades of grey to be converted into colours which are
projected onto a large screen thus representing the output from the computer.

LCD Projectors
It uses a high intensity beam of light shown through three layers of changing pixel.

 A powerful beam of white light is generated from a bulb or LED inside the projector body.
 This beam of light is then sent to a group of chromatic-coated mirrors (known as dichromic
mirrors); these reflect the light back at different wavelengths.
 When the white light hits these mirrors, the reflected light has wavelengths corresponding to
red, green and blue light components.
  These three different coloured light components pass through three LCD screens (each screen is
composed of thousands of tiny pixels which can either block light or let it through; this produces
a monochromatic image).
 Consequently, three different versions of the same image are now produced – one is the whole
image in different shades of red, one is the whole image in different shades of green and one is
the whole image in different shades of blue.
 These images are then re-combined using a special prism to produce a full colour image.
 finally, the image passes through the projector lens onto a screen.

Advantages and disadvantages of DLP and LCD projectors

Liquid Crystal Display (LCD)

Most monitors and television sets these days are made using LIQUID CRYSTAL DISPLAY/DIODE (LCD)
technology.

 Liquid crystal display

 The display is made of pixels means arranged in a matrix
 Uses a flat panel display
 Backlit display with CCFLs/LEDs
 Uses light modulating properties of liquid crystals
 Crystals can be turned between opaque and transparent (to allow light to pass)
 Colors created using RGB

Benefits Of Using LCD

 Low power consumption
 Runs at cool temperature
 Do not suffer image burn
  Bright image/Colour
 High Resolution image
 Cheaper to purchase than e.g LED screen

This means that the front layer of the monitor is made up liquid crystal diodes; these tiny diodes are
grouped together in three or fours which are known as pixels (picture elements). The three colours
which are grouped together use(RGB) red, green and blue diodes. Those systems that use groups of four
include a yellow diode – this is sad to make the colour more vivid.

Light Emitting Diode

Modern LCD monitors are back lit using LIGHT EMITTING DIODE (LED) technology, This give the image
better contrast and brightness.

Benefit Of Using LED

 Reaches maximum brightness quickly
 No need to warm up
 Colours are vivid
 Good colour definition / contrast can be achieved
 Screens can be thinner / thin
 Consume very little / less energy
 Higher resolution

Organic Light Emitting Diode

The acronym ‘OLED’ stands for Organic Light-Emitting Diode - a technology that uses LEDs in which the
light is produced by organic molecules. These organic LEDs are used to create what are considered to be
the world’s best display panels.

Benefit Of Using OLED

 They allow for very thin and very flexible screens which are very light weight
 They produce a much brighter light than LEDs
 They don’t required any form of back-lit
 They allow for a much larger field of view
DATA STORAGE
Primary Memory
Directly access by CPU

There are two types of primary memory

RAM ROM
Random Access Memory Read Only Memory
Temporary memory (Volatile) Permanent memory (Non-Volatile)
There are two types of RAM Boot-up / start up instruction
 SRAM
 DRAM
There are three types of ROM
 PROM
 EPROM
 EEPROM

Secondary Memory
Not directly access by CPU

There are two types of primary memory

Hard Disk Drive (HDD) Solid State Drive (SSD)

Noisy Quieter
Cheap Expensive
Trusted technology Not trusted technology
Slow data access Fast data Access
Heat Cool

Offline Memory
 CD
 DVD
 USB
 SD Card
 Cloud storage
Cloud Storage
Cloud storage allows us to store data remotely and access it from any device through an internet

Advantages Disadvantages
It increase the productivity and efficiency you can Internet connection is needed
also backup data safely through a cloud way
It makes collaboration and data sharing easier No control over security
without over investing

IPv4 and IPv6

IPv4 IPv6
Represents in “Denary” Represents in “Hexa”
192.168.0.1 CA00:2235:ABE0:8721
32 bit binary address 128 bit binary address
Separator (.) DOT Separator (:) COLON
Now a days technology Future technology