Chapter 7: Printers and Scanners

1. Chapter 7: Printers and Scanners IT Essentials: PC Hardware and Software v4.0

2. Chapter 7 Objectives 7.1 Describe the types of printers currently available 7.2 Describe the installation and configuration process for printers 7.3 Describe the types of scanners currently available 7.4 Describe the installation and configuration process for scanners 7.5 Identify and apply common preventive maintenance techniques for printers and scanners 7.6 Troubleshoot printers and scanners

3. Chapter 7 Labs • 7.4.2 Lab: All-in-One Device

4. 7.1 Introduction • Printers produce paper copies of electronic files. • Hard copies of computer documents remain important today. • Scanners allow users to convert paper documents intoelectronic files.

5. Types of Printers • Computer technicians should know how to purchase, repair, or maintain a printer. • A customer may request a technician to: • Select a printer • Install and configure a printer • Troubleshoot a printer

6. Printers: Speed and Capacity Printers available today are: • Laser printers using electrophotographic technology • Inkjet printers using electrostatic spray technology • Dot matrix printers using impact technology • Used in applications that require multiple (“carbon”) copies • Printer speed is measured in pages per minute (ppm): • Inkjet Printer 2 - 6 ppm • Laser Printer 8 - 200 ppm • Price of a printer reflects its capacity and speed

7. Color wheel Printers: Color and Quality • The choice between a black-and-white printer and a color printer depends on the needs of customers. • A printer produces colors using subtractive mixing. • The eye sees a color that reflects from the combination of colors on the paper. • The colors are cyan, magenta, yellow, and black (CMYK). • Quality is measured in dots per inch (dpi). • The more dpi, the higher the resolution

8. Printers: Reliability and Cost • Factors of reliability include: • Warranty • Scheduled servicing • Mean time between failures (MTBF) • Total Cost of Ownership (TCO) includes: • Initial purchase price • Cost of supplies, such as paper and ink • Price per page • Maintenance costs • Warranty costs • The amount of material to be printed • The expected lifetime of the printer

9. Printer to Computer Interfaces To access a printer, a computer must have an interface with it. The following are common interface types: • Serialdata transfer is the movement of single bits of information in a single cycle. • Serial ports are D-shell and are either male or female ports • Maximum length of a serial cable is 50 ft. • Parallel data transfer is the movement of multiple bits of information in a single cycle. • Parallel data transfer is faster than serial data transfer • Maximum length of a parallel cable is 15 ft. • Small Computer System Interface (SCSI), pronounced “scuzzy”, uses parallel communication to achieve high data-transfer rates. • Universal Serial Bus (USB) is a common interface for printers and other devices.

10. More Interface Types • Firewire is also known as i.LINK or IEEE 1394 and is a high-speed, communication bus that is platform independent. Firewire devices are hot-swappable. • Ethernet is an interface for network printers, which are usually a resource shared on a network. • Wireless printing technology: • Infraredrequires transmitters and receivers on both devices, a clear line of sight between the transmitter and receiver, and a maximum distance of 12 ft. • Bluetooth technology uses an unlicensed radio frequency for short-range communication. • Wi-Fi or IEEE 802.11is a standard for wireless communication.

11. Laser Printers • A laser printer is a high-quality, fast printer that uses a laser beam to create an image. • The main components contained within a laser printer: • Toner cartridge • Laser scanner • High-voltage power supply • Paper transport mechanism • Transfer corona • Fuser assembly • Control circuitry • Ozone filter • NOTE: You should know the components of a laser printer and the steps required to print a page.

12. Laser Printing Process • The laser printer process involves six steps to print information onto a single sheet of paper

13. Laser Printer Operation 1. Cleaning 2. Conditioning 3. Writing 4. Developing 5. Transferring 6. Fusing Continuous Care Will Delay Trouble Forever CaliforniaCowsWon’tDanceTheFandango! CleanCorvettesWillDriveTooFast!

14. Laser Printer Operation • Cleaning – When an image has been deposited on the paper and the drum has separated from the paper, any remaining toner must be removed from the drum. • One method uses a blade to scrape all excess toner from the drum. • Other printers use an AC voltage on a wire that removes the charge from the drum surface and allows the excess toner to fall away from the drum. The excess toner is stored in a used toner container that may be emptied and/or discarded.

15. Laser Printer Operation 2. Conditioning – This step involves removing the old latent image from the drum and clearing or conditioning the drum for a new latent image. Placing a special wire, grid, or roller that is charged to about -6000 volts DC uniformly across the surface of the drum accomplishes this. This charged wire or grid is referred to as the primary corona. Some printers provide this charge by using a conditioning roller. The charge impressed upon the surface of the drum is -600 to -1000 volts DC.

16. Laser Printer Operation 3. Writing – This process involves scanning the photosensitive drum with the laser beam. Every portion of the drum that is exposed to the light has the surface charge reduced to about -100 Volts DC. This electrical charge has a lower negative charge than the remainder of the drum. As the drum turns, an invisible latent image is created on the drum. The figure shown illustrates the various voltage transitions involved with creating a printed page in the laser printing process.

17. Laser Printer Operation 4. Developing –This is the step where the toner is transferred to the latent image. Inside the toner unit is developer particles made up of magnetic materials. These magnetic particles are coated with a plastic-like material. A turboelectric charge on the developer particles causes it to attract toner. The toner as, a result, is charged to around -200 volts DC, which causes it to be attracted to the more positive (-100 volts DC) areas of the photosensitive drum, but repelled by the more negative (-600 volts DC) areas.

18. Laser Printer Operation 5. Transferring – In this step, the toner attached to the latent image is transferred to the paper. The transfer, or secondary corona, places a positive charge on the paper (remember the drum was charged negatively) so that it attracts the negative toner image from the drum to the paper. The image is now on the paper and is held in place by the positive charge.

19. Laser Printer Operation 6. Fusing – The toner particles on the paper are only there because of the charge that is present. They are kept in place permanently by the "fusing process". In this process, the printing paper is rolled between a heated roller and a pressure roller. As the paper rolls, the top fuser roller is heated to about 350 degrees. This melts the plastic, which is mixed with the carbon black to make toner, onto the paper. This operation is called fixing by some manufacturers. After the fusing operation is complete, the paper is moved to the output tray, as a printed page. The fuser is very hot to the touch after printing.

20. Typical Laser Printer Mechanism

21. WARNING • The primary corona wire or grid, or the conditioning roller, can be very dangerous. • The voltage runs as high as -6000 volts. • Only certified technicians should work on the unit. • Before working inside a laser printer, you should make sure that voltage is properly discharged.

22. Page Description Languages • Page description language (PDL) is a code that describes the contents of a document in a language that a printer can understand. These contents include text, graphics, and the overall formatting of the document. PDLs are used by software applications to send What You See Is What You Get (WYSIWYG) images to the printer so that the printer output mirrors the document laid out on the screen. • Printer Control Language (PCL) – PCL was developed by Hewlett-Packard (HP) to allow software applications to communicate with HP and HP-compatible laser printers, inkjet printers, and plotters. It is the standard PDL upon which many others are based.

23. Page Description Languages • PostScript (PS) – PS was developed by Adobe Systems to allow fonts or text types to share the same characteristics on screen as well as on paper. • PCL drivers do most of the rendering on the local workstation and the information is sent in essentially binary form to printer. Postscript drivers essentially send a page description to the printers where it is rendered. Since local workstations are generally MUCH faster than the printers, PCL printing is much faster than postscript; and because it requires less printer memory, some jobs may only print if sent using PCL drivers. However, PCL is also a simpler language than Postscript so it lacks many of the complex drawing and scaling functions that are available in Postscript. Therefore, if you are using a package which takes advantage of postscript's capabilities (e.g. most Adobe products and some others), you may get better quality output using postscript drivers and your complex print job may not print properly or at all using the PCL driver. • Interpress – Interpress was developed by Xerox to handle its line of high-speed laser printers.

24. Ink and Toner Installation and Replacement • Laser printer toner units should be shaken vigorously in a side-to-side manner to evenly distribute the toner inside the hopper. If toner spills out of the cartridge, it can be wiped up with a damp cloth. • Inkjet printer cartridges can be fragile. Be sure to handle with care and do not touch the printhead or foil contacts. This could clog the nozzles and cause erratic output. Also, be sure to install the correct color cartridge in the correct slot in the printer. • Printer ribbons should be handled on the plastic ends only. Never touch the actual ribbon. • Check the expiration date. Many manufacturers include an expiration date on their cartridges. After this date, the ink cartridge will work erratically or not at all, even with the remaining ink. Any guarantee is void after this date. • Ink cartridges, toner units, and ribbons should be recycled according to the environmental recommendations. Manufacturers will typically include the packing material to send back toner units.

25. Impact Printers • Impact printersform characters when the print head impacts a printer tape or inked ribbon to create characters. (Daisy-wheel and dot-matrix printers) • Advantages: • Uses inexpensive consumables • Uses continuous feed paper • Has copy printing ability (“carbon copies”) • Disadvantages: • Noisy • Low resolution graphics • Limited color capability • Slow printing, normally 32 to 76 characters per second (cps)

26. Inkjet Printers • Use ink-filled cartridges that spray ink onto a page through tiny holes, or nozzles. The ink is sprayed in a pattern on the page, one column of dots at a time. • Produce high quality print • Easy to use • Inexpensive compared to laser printers • Two types of inkjet nozzles: • Thermal - A pulse of electrical current is applied to heating chambers around the nozzles. The heat creates a bubble of steam in the chamber which forces ink out through the nozzle. • A charge is applied to piezoelectric crystals, located in the ink reservoir at the back of each nozzle. This charge causes the crystals to vibrate. The vibration controls the flow of ink onto the paper.

27. Inkjet Printer Components • A feeding mechanism draws paper in and the paper passes by the print head where ink is sprayed onto it. • Paper leaves the printer through the discharge mechanism, and is wet for about 15 seconds.

28. Solid-Ink Printers Use solid sticks of ink rather than toner or ink cartridges • The printing process: • Step 1: Cleaning • Step 2: Spraying • Step 3: Transferring • Advantages: • Produces vibrant color prints • Easy to use • Can use many different paper types • Disadvantages: • Expensive (the printer and ink) • Slow to warm up

29. Thermal Printers • A thermal printer uses chemically-treated paper that becomes black when heated. • A thermal transfer printer uses heat-sensitive ribbon, which the print head melts onto the paper. • Thermal printers have a longer life because there are few moving parts. • Disadvantages: • Paper is expensive • Paper has a short shelf life • Images are poor quality • Paper must be stored at room temperature

30. Dye-Sublimation Printers • Also called thermal dyeprinters • Usually used in producing photo-quality images for graphic printing • Uses solid sheets of ink that change directly from solid to gas when heated, in a process called sublimating • Advantages: • Very high quality images • Overcoat layer reduces smearing, increases moisture resistance • Disadvantages: • Media can be expensive • They are better for color than for grayscale (black and white)

31. 7.2 Installation and Configuration of Printers When purchasing a printer, the installation and configuration information is usually supplied by the manufacturer. • An installation CD that includes drivers, manuals, and diagnostic software • Also available as downloads from the manufacturer's website

32. How to Set Up a Printer Check the box to ensure all required cables are provided. Remove packing materials from the printer and plastic inserts from the consumables. Place printer in position. Ensure that the printer location will not cause overheating. Install paper trays. Install paper. Read and follow the instruction manual . Connect cables. Test print from computer.

33. Power and Connect the Printer Connect the appropriate data cable to the communication port on the back of the printer. Attach the power cable to the printer and the other end to an available electrical outlet. Warning: Never plug a printer into a UPS. The power surge that occurs when the printer is turned on will damage the UPS unit.

34. Printer Driver Printer driver is the software program that enables the computer and the printer to communicate with each other. Find out if a newer driver is available on the manufacturer’s website Download the driver files to your computer Install the driver automatically or manually Test the new printer driver

35. Printer Firmware • Firmware is a set of instructions stored on the printer to control how the printer operates. • If printing problems occur or you need new features, consider upgrading the printer's firmware. • Download the upgrade file from the manufacturer's website and run a setup file to install it.

36. Printer Memory • Printer memory is used to buffer print jobs, create pages, or draw images for documents. • Adding printer memory can improve printing speed and allow the printer to handle more complex print jobs. • Print-job buffering is the ability of the printer to capture as much of the print job into its internal memory as possible. • Consult the documentation for memory requirements: • Memory specifications • Memory population and availability

37. Upgrade Printer Memory Turn off the printer. Disconnect all cables. Open the memory compartment. Replace memory modules or add new modules. Close the memory compartment. Reconnect all cables. Power on printer. Run a self-test. Print a test page.

38. Configuration Options and Defaults Common printer settings: • Paper type • Print quality • Color printing • Black-and-white printing • Grayscale printing • Paper size • Paper orientation • Print layout • Duplex

39. Optimize Printer Performance • Print spool settings • You may store documents that are prepared for printing in a file in RAM called the print spool. • Spooling programs allow the application you are printing from to finish faster. You may also print directly to the printer. • Printer calibration • You can adjust settings to match the colors seen on the screen and the colors on printed sheet. • Paper orientation • You can select landscape or portrait image layout.

40. Print a Test Page • Print a test page to verify the following: • The printer is operating properly • The driver software is installed and working correctly • The printer and computer are communicating • To print a test page manually: • Start > Printers and Faxes • In the Printers and Faxes window, right-click the desired printer and follow this path: Properties > General Tab > Print Test Page • A dialog box will open, asking if the page printed correctly. If it did not, then built-in Help will assist you in troubleshooting the problem.

41. Print from an Application • To print from Notepad: • Start > Programs > Accessories > Notepad • A blank document will open. • Enter some text in the document. • File > Print

42. Test a Printer from the Command Line • Printing from the command line is limited to ASCII files only, such as .txt and .bat files. • To send a file to the printer from the command line, use this path: Start > Run • The Run box should pop up. Type cmd in the Run box, and then click OK. • At the command line prompt, enter the following command: Print thefile.txt

43. Test Printer from Printer Panel • Most printers have a front panel with controls to allow you to generate test pages. • This method of printing enables you to verify the printer operation separately from the network or computer. • Consult the printer manufacturer's website or documentation to learn how to print a test page from the front panel of the printer.

44. Sharing a Printer • Printer sharing enables multiple network users or clients to access a printer. Windows 2000/XP installs the print sharing capability in the basic setup.

45. Printer Sharing • Click Start > Printers and Faxes. • Right-click the printer and choose Properties. • Select the Share tab. • Click the Share this printerradio button. • Keep or change share name. • Click Apply. To connect to the shared printer from another computer:Choose Start > Printers and Faxes > Add PrinterFollow the steps using the Add Printer Wizard

46. 7.3 Types of Scanners • Technicians may be required to purchase, repair, or maintain a scanner. • The following are tasks that a customer may request: • Select a scanner • Install and configure a scanner • Troubleshoot a scanner

47. Flatbed scanner Handheld scanner All-in-one scanner Drum scanner Types of Scanners • Scanners convert printed data or images into an electronic data format that a computer can store or process as required. • A scanned image can be saved, modified, and even e-mailed as you would with any other file.

48. Resolution and OCR • Features, quality, and speed of scanners vary. • Scanners typically create an RGB image that can be converted into image formats such as JPEG, TIFF, Bitmap, and PNG. • An RGB image has three channels: red, green, and blue. • Some scanners can create text documents using optical character recognition (OCR). • OCR software is used to convert a scanned printed page into text that can be edited with a word processor. • Resolution of a scanner is measured in dots per inch (dpi). Like printers, the higher the dpi, the better the quality of the image.

49. Serial USB Firewire Parallel (Centronics and DB-25) Interfaces and Cables • To allow communication of data, the scanner and computer must have compatible interfaces. • Interfaces and cables used for printers are typically the same as those used for scanners.

50. All-in-one Scanners • An all-in-onedevice combines the functionality of multiple devices into one physical piece of hardware. • Scanner, Printer, Copier, and/or Fax • Advantages: • All devices are built in • Low cost • One upgrade for all devices • Easy connection and setup • Uses one port for all devices • Disadvantages: • One problem effects all devices • Not designed for heavy use