Submitted ToSubmitted To:: Engr.Hafiz Khuram AliEngr.Hafiz Khuram Ali

Submitted BySubmitted By:: Ehtesham Ayoub 07-MCT-32Ehtesham Ayoub 07-MCT-32

Hafiz Abd-Ur-Rauf 07-MCT-19Hafiz Abd-Ur-Rauf 07-MCT-19

Farhan Nawaz 07-MCT-39Farhan Nawaz 07-MCT-39

CONTENTSCONTENTS What is fax?What is fax? HistoryHistory OverviewOverview CapabilitiesCapabilitiesi)i) GroupGroupii)ii) ClassClassiii)iii) Data transmission rateData transmission rateiv)iv) CompressionCompressiona)a) Modified HuffmanModified Huffmanb)b) Modified ReadModified Readc)c) Matsushita White line SkipMatsushita White line Skip Working of fax machineWorking of fax machine Alternatives Alternatives How to Use, Advantages and Disadvantages.How to Use, Advantages and Disadvantages.

WHAT IS FAXWHAT IS FAX? ?

FaxFax-“facsimile-“facsimile" (Latin word)" (Latin word) “make “make copy”-copy”-is is a process of converting optical a process of converting optical images into electrical signals for transmission images into electrical signals for transmission over communication systems (phone line, over communication systems (phone line, internet etc). internet etc).

Principal:Principal:

Image convert into electrical signals by a Image convert into electrical signals by a mechanical phenomena. mechanical phenomena.

Signal convert to a hard copy by a mechanical Signal convert to a hard copy by a mechanical phenomena.phenomena.

History:History:

In 1850, a London inventor named F. C. Blakewell In 1850, a London inventor named F. C. Blakewell received a patent what he called a "copying received a patent what he called a "copying telegraph".telegraph".

By 1926, RCA invented the Radiophoto that faxed by By 1926, RCA invented the Radiophoto that faxed by using radio broadcasting technology. using radio broadcasting technology.

In 1947, Alexander Muirhead invented a very In 1947, Alexander Muirhead invented a very successful fax machine.successful fax machine.

On March 4, 1955, the first radio fax transmission On March 4, 1955, the first radio fax transmission was sent across the continent.was sent across the continent.

Overview:Overview:

Parts:Parts:

A "fax machine" usually consists of the A "fax machine" usually consists of the following parts;following parts;

Image ScannerImage Scanner ModemModem PrinterPrinter Phone Line.Phone Line.

1-1-Image Scanner:Image Scanner:The scanner converts the content The scanner converts the content

printed on a physical documentprinted on a physical document

into a digital imageinto a digital image. Image and . Image and

text capture (optical character text capture (optical character

recognition or OCR) allow you to recognition or OCR) allow you to

save information.save information.

2-2-Modem:Modem:The modem sends the imageThe modem sends the image

data over a phone line to data over a phone line to

another device.another device.

3-3-Printer:Printer:The printer at the far end produces a copy of the The printer at the far end produces a copy of the

transmitted document.transmitted document.

4-4-PhonePhoneLine:Line:The phone receive and sends The phone receive and sends signals of documents intosignals of documents into digital forms.digital forms.

CAPABI LITIESCAPABI LITIES::1.1. Group Group

2.2. Class Class

3.3. Data transmission rate Data transmission rate

4.4. CompressionCompression

1.1.GROUP:GROUP:

There are two types of groupsThere are two types of groups..

I. AnalogI. Analog

II.DigitalII.Digital

2.CLASS:2.CLASS:

Computer modems are often designated by a Computer modems are often designated by a particular fax class, which indicates how much particular fax class, which indicates how much processing is offloaded from the computer's processing is offloaded from the computer's CPU to the fax modem.CPU to the fax modem.

3.Data transmission rate:3.Data transmission rate:Different telephone line modulation techniques Different telephone line modulation techniques

are used by fax machines, and will use the data are used by fax machines, and will use the data rate in kbits/s.rate in kbits/s.

4.Compression:4.Compression:

Two compression methods for decreasing the Two compression methods for decreasing the amount of data that needs to be transmitted amount of data that needs to be transmitted between the fax machines to transfer the between the fax machines to transfer the image. image.

The two methods are:The two methods are: Modified Huffman (MH) Modified Huffman (MH) Modified READ (MR)Modified READ (MR)

Modified HuffmanModified Huffman::Modified Huffman (MH) is a codebook-based run-length Modified Huffman (MH) is a codebook-based run-length

encoding scheme optimized to efficiently compress white encoding scheme optimized to efficiently compress white space.space.

Modified Read:Modified Read:This encodes the first scanned line using MH. The next line is This encodes the first scanned line using MH. The next line is

compared to the first, the differences determined, and then the compared to the first, the differences determined, and then the differences are encoded and transmitted.differences are encoded and transmitted.

EEffective as most lines differ little from their predecessor.ffective as most lines differ little from their predecessor. The limited number of lines is two for 'Standard' The limited number of lines is two for 'Standard'

resolution faxes, and four for 'Fine' resolution faxes.resolution faxes, and four for 'Fine' resolution faxes.

Matsushita White line Skip:Matsushita White line Skip:

A proprietary compression scheme employed on A proprietary compression scheme employed on Panasonic fax machines is Matsushita White Panasonic fax machines is Matsushita White line Skip (MWS).line Skip (MWS).

It is operative only when two Panasonic It is operative only when two Panasonic machines are communicating with one machines are communicating with one another.another.

Detects Detects blank scanned areas between lines of blank scanned areas between lines of texttext & convert & convert into the data space of a single into the data space of a single character.character.

Basic Idea Behind Fax MachinesBasic Idea Behind Fax Machines:: Rotating Drums:Rotating Drums:

Attaching the paper with drums. Attaching the paper with drums. And paper move with rotating arms And paper move with rotating arms of drums.of drums.

PHOTO SENSORPHOTO SENSOR::

Photo sensor able to focus in and look Photo sensor able to focus in and look at a very small spot on the piece of at a very small spot on the piece of paper. And also sense white and paper. And also sense white and colored parts of the sending colored parts of the sending document paper.document paper.

Working of Modern Fax Working of Modern Fax MachinesMachines::

The main parts of working of a modern fax The main parts of working of a modern fax machine having the following mechanism.machine having the following mechanism.

Sensing the documentSensing the document.. Encoding the document.Encoding the document. Transmission of document.Transmission of document. Marking the paper.Marking the paper.

The scanning process: The scanner in a fax machine looks at one line of the sheet of paper. The scan line is shown here in red. It sees a group of black and white spots, shown blown up in the red rectangle at the bottom of the figure. It encodes the pattern of spots and sends them through the phone line.

Internet fax.Internet fax.

Wireless fax.Wireless fax.

Alternatives:Alternatives:

Internet FaxInternet Fax::

Wireless FaxWireless Fax::

Characteristics of A Fax MachineCharacteristics of A Fax Machine::

A good fax machine should have following A good fax machine should have following characteristic;characteristic;

It should communicate to other fax machines.It should communicate to other fax machines. It has a horizontal resolution of 203 pixels per It has a horizontal resolution of 203 pixels per

inch (8 pixels/mm). inch (8 pixels/mm).

It has three different vertical resolutions; It has three different vertical resolutions; StandardStandard: 98 lines per inch (3.85 lines/mm) : 98 lines per inch (3.85 lines/mm) Fine:Fine: 196 lines per inch (7.7 lines/mm) 196 lines per inch (7.7 lines/mm) Super fineSuper fine (not officially a Group 3 (not officially a Group 3

standard, but fairly common): 391 lines per standard, but fairly common): 391 lines per inch (15.4 lines/mm) inch (15.4 lines/mm)

It can transmit at a maximum data rate of It can transmit at a maximum data rate of 14,400 bits per second (bps)14,400 bits per second (bps) to minimum to minimum range of 2,400 bps if there is a lot of noise range of 2,400 bps if there is a lot of noise on the line.on the line.

Sending of a FaxSending of a Fax:: Turn ON.Turn ON. Obtain the number of the destinationObtain the number of the destination Gather documents you want to send.Gather documents you want to send. A cover sheet with following instructionsA cover sheet with following instructions Recipient’s name & fax NO.Recipient’s name & fax NO. Sender’s name & phone NO.Sender’s name & phone NO.

How to Receive A FaxHow to Receive A Fax?? Fax machine has enough ink in its toner Fax machine has enough ink in its toner

cartridge.cartridge. Enough printer paper loaded in paper tray.Enough printer paper loaded in paper tray. Then phone will ring. Don’t pick up.Then phone will ring. Don’t pick up. Wait for the Handshake tones.Wait for the Handshake tones. It automatically begin to print each page.It automatically begin to print each page. Check the cover sheet.Check the cover sheet.

Trouble Shooting of FaxTrouble Shooting of Fax:: Image quality.Image quality. Image can be too dark or too light.Image can be too dark or too light. Leaking of toner.Leaking of toner.

Paper jam.Paper jam. Document FeederDocument Feeder Printing area.Printing area.

Connectivity issues.Connectivity issues. Check dial tone & also phone line.Check dial tone & also phone line.

Advantages:Advantages:

Faxes have a distinct advantage over postal Faxes have a distinct advantage over postal mail in that the delivery is nearly mail in that the delivery is nearly instantaneous.instantaneous.

Can be delivered at any time.Can be delivered at any time. No need to give commands of printing No need to give commands of printing

separately on receiving the fax document.separately on receiving the fax document.

Disadvantages:Disadvantages:

Need a separate space for the machine. Need a separate space for the machine. Needs a telephone line. Needs a telephone line. Needs power/electricity Needs power/electricity Requires paper for receiving and sending faxes Requires paper for receiving and sending faxes Aging of papers could lead to difficulties in Aging of papers could lead to difficulties in

managing records. managing records.