Printer Technologies and Installation

1. Printer Technologies and Installation Chapter 19

2. Overview In this chapter, you will learn how to Describe current printer technologies Explain the laser printing process Install a printer on a Windows PC

3. Six Types of Printers Impact printers Inkjet printers Dye-sublimation printers Thermal printers Solid ink printers Laser printers

4. Impact Printers Impact printers leave an image on the paper Physically strike an inked ribbon against the surface of the paper Relatively slow and noisy Used for multipart forms Point of sale receipts Offices

5. Dot-Matrix Printers Dot-matrix printers Use an array of pins known as printwires to strike an inked printer ribbon and produce images The case that holds the print wires is called the printhead Use either 9-pin (draft quality) or 24-pin (letter ornear-letter quality)

6. Dot-Matrix Printers (continued) Figure 1: An Epson FX-880+ dot-matrix printer (photo courtesy of Epson America, Inc.)

7. Dot-Matrix Printers (continued) Figure 2: Inside a dot-matrix printer

8. Inkjet Printers • An inkjet printer uses a printhead connected to a carriage that contains the ink. A belt and motor move the carriage back and forth so the ink can cover the whole page. A roller grabs paper from a paper tray (usually under or inside the printer) or feeder (usually on the back of the printer) and advances it through the printer.

9. Inkjet Printers (continued) Figure 3: Typical inkjet printer

10. Inkjet Printers (continued) Inkjet printers Simple devices that consist of the following: Printhead, support electronics, a transfer mechanism, and a paper-feed component Work by ejecting ink through tiny tubes Ink is heated by tiny resistors or electroconductive plates at the end of each tube. The resistors or plates boil the ink, which creates a tiny air bubble that ejects a droplet of ink onto the paper. Some inkjets use mechanical methods to eject ink. Most color printers are inkjet and produce a high-quality image.

11. Inkjet Printers (continued) Figure 4: Inside an inkjet printer

12. Inkjet Printers (continued) Figure 5: Detail of the inkjet printhead

13. Inkjet Printers (continued) Older inkjets had two ink cartridges Black Color Newer ones have four Black Cyan Magenta Yellow Or more . . . Still outrageously expensive Cost of replacements more than cost of printer!

14. Inkjet Printers (continued) Figure 6: Inkjet ink cartridges

15. Print resolution Density of the ink Dots per inch (dpi) Print speed Pages per minute (ppm) Can print to almost anything Modern inks of archival quality (200+ years) Inkjet Key Features

16. Dye-Sublimation Printers Dye-sublimation printers (or thermal dye transfer printers) use sublimation. Sublimation causes something to change from a solid form into a vapor. Desublimation changes the vapor back to a solid. Used for fine detail and rich color Requires one pass for each color Produces high-quality output

17. Dye-Sublimation Printers (continued) Uses CMYK method of printing Cyan, magenta, yellow, black Roll of heat-sensitive plastic film embedded with dye Fine printhead that vaporizes the dyes onto special paper Requires four passes to complete Creates continuous tone images Other processes create dithered images where the dots fake the blended colors. Professional-caliber output

18. Dye-Sublimation Printers (continued) Figure 7: The dye-sublimation printing process

19. Thermal Printers Thermal printers Two types: direct thermal and thermal wax Direct thermal Same as first generation of fax machines Use a heated printhead to burn dots into the surface of special heat-sensitive paper Still used for receipts at some businesses Thermal wax transfer Like dye-sublimation printers Use film coated with colored wax that gets melted onto page No need for special paper But dithered images

20. Laser Printers Laser printers use a mechanism called electro-photographic imaging. Produce high-quality and high-speed output of both text and graphics More expensive to purchase than inkjet or impact printers Far less expensive over the lifespan of the printer when you factor in consumables Use lasers as a light source

21. Laser Printers (continued) Figure 8: Typical laser printer

22. Laser Printer Parts Toner cartridge Holds the toner Many other parts that suffer the most wear and tear are contained in the toner cartridge. Photosensitive drum Aluminum cylinder coated with particles of photosensitive compounds Erase lamp Exposes the entire surface of the photosensitive drum to light, draining any electrical charge

23. Laser Printer Parts (continued) Figure 9: Components inside a laser printer

24. Laser Printer Parts (continued) Figure 10: Laser printer’s toner cartridge

25. Primary corona/charge roller Enables voltage to pass to the drum and charge the photosensitive particles on its surface Creates a uniform negative charge (~600 to ~1000 volts) Laser Acts as the writing mechanism of the printer Discharges areas on drum to negative ~100 volts Laser Printer Parts (continued)

26. Toner Fine powder made up of plastic particles bonded to iron particles Charged by toner cylinder to negative ~200 to ~500 volts Attracted to the parts of the drum struck by the laser Laser Printer Parts (continued)

27. Transfer corona/transfer roller Applies a positive charge to the paper Negatively charged toner is attracted to the positively charged paper. Static eliminator removes charge. Fuser assembly Attaches the toner permanently to the paper using a pressure roller and heated roller Laser Printer Parts (continued)

28. Primary power supply Provides power to the motors that move the paper, system electronics, and transfer corona High-voltage power supply Provides power to the primary corona When inserting a new toner cartridge, always turn the laser printer off before opening it. Turning gears Discrete units called gear packs or gearboxes Laser Printer Parts (continued)

29. System board Contains the main processor, ROM, and RAM ROM can often be flashed. Insufficient RAM can result in memory overflow error. Ozone filter Ozone (O3) generated by coronas can damage printer components. Filter needs to be replaced periodically. Sensors and switches Detect paper jams, empty paper trays, low toner levels, and so on Laser Printer Parts (continued)

30. Solid Ink Printers Use solid sticks of non-toxic “ink” Produces vibrant color Ink is melted and absorbed into the paper fibers. Only needs a single pass More expensive than other printers But ink sticks are significantly less expensive than inkjet cartridges.

31. Printer Languages American Standard Code for Information Interchange (ASCII) Basic alphanumeric characters and a variety of control codes for transferring data and controlling printers Limited in its capability The PostScript page description language (PDL) developed by Adobe Device-independent printer language capable of high-resolutions and scalable fonts Printers print faster because most of the image processing is done by the printer and not the PC;PostScript defines page as single raster image. PostScript files are very portable.

32. Printer Languages (continued) Hewlett Packard developed the Printer Command Language (PCL). Expanded set of printer commands Dependent on the printer hardware Does not support advanced graphical functions Does not define the page as a single raster image

33. Printer Languages (continued) Windows XP uses the Windows graphical device interface (GDI). The operating system handles print functions. If the printer has a capable raster image processor and enough RAM, you don’t need to worry about the printer language. Windows Vista and 7 use the XML Paper Specification (XPS) print path. XPS provides improved color management and print layout fidelity. Vista and 7 also still support GDI.

34. Printer Connectivity Most local printers connect to one of two ports on the PC. DB-25 parallel port USB port Ethernet and Wi-Fi are becoming more common. The parallel port was a lot faster than the existing serial ports at the time. But it is slow by today’s standards, with a maximum data transfer rate of 150 KBps. Standard parallel ports lack bidirectional capabilities.

35. IEEE 1284 Standard The IEEE 1284 standard defines a high-speed bidirectional parallel port with backward compatibility. The IEEE 1284 standard requires Support for five modes of operation Compatibility mode, nibble mode, byte mode, EPP, ECP Standard methods of negotiation for determining which modes are supported A standard physical interface A standard electrical interface

36. Setting Up Parallel Ports Use the System Setup utility to configure parallel ports built into motherboards. Three options SPP (150 KBps transfers) ECP (~ 2 MBps transfers) EPP (~2.5 MBps transfers) Choose the option that best fits your device (e.g., ECP for the last generation of parallel laser printers).

37. Parallel Connections, Cabling, and Electricity A standard printer cable A male DB-25 connector on one end and a 36-pin Centronics connector on the other Acceptable for transferring data at 150 KBps at distances of less than6 feet IEEE 1284-compliant cable Can be up to 32 feet (10 m) Required for bidirectional printing

38. Parallel Connections, Cabling, and Electricity(continued) Figure 11: Standard parallel cable with 36-pin Centronics connector on one end and DB-25 connector on the other

39. USB Printers Most new printers use USB connections. Most use USB type A on one end and USB type B on the other end.

40. Network and Other Printers Printers can be connected on a network. Needs NIC and connection (typically RJ-45) Needs IP address (either manually assigned or automatically assigned from DHCP) Can be connected to print server Some also have wireless, IR, and Bluetooth capabilities. Other printers Rare, but may see serial or SCSI printers

41. Click [Print]. CPU sends print job to print spooler. Spooler can handle multiple print jobs in the print queue. Spooler is a service. Killing the spooler service deletes all print jobs. Print device takes it from there. The Electronic Printing Process

42. Raster image Impact printers print a line at a time. Laser printers generate a raster image of the page. A raster image is a pattern of dots. The raster image processor (RIP) chip translates the raster image into commands for the laser printer. The Electronic Printing Process (continued)

43. The Electronic Printing Process (continued) RIP needs RAM in order to store this data. Mem Overflow error indicates insufficient RAM. Add RAM, reduce the resolution, or print smaller graphics. HP LaserJet 21 error means the data is too complex. Reduce complexity by using fewer fonts and less formatting, reducing graphics resolution, and so on. Resolution enhancement technology (RET) Enables the printer to insert smaller dots among the characters to smooth out jagged curves. Disabling RET helps reduce MEM OVERFLOW errors.

44. Resolution A laser printer can print at different resolutions. Resolution is expressed in dots per inch (dpi)—for example, 600 × 600 or 1200 × 1200 dpi. The first number is the horizontal resolution—how fine a focus can be achieved by the laser. The second number is the vertical resolution—the smallest increment by which the drum can be turned. The Electronic Printing Process (continued)

45. The Electronic Printing Process (continued) Figure 12: RET fills in gaps with smaller dots to smooth out jagged characters.

46. Physical Side of the Process Six steps of the physical laser printing process Charging Exposing Developing Transferring Fusing Cleaning

47. The drum is charged by applying a negative charge to the entire surface. Charged by primary corona wire Between ~600 and ~1000 volts Charging the Drum

48. Charging the Drum (continued) Figure 13: Charging the drum with a uniform negative charge

49. Exposing and Developing the Image A laser is used to write and develop an image on the surface of the drum. Every particle hit by the laser releases most of its negative charge into the drum. Toner is attracted to the more positively charged areas of the drum; this is the develop portion of the process.

50. Exposing and Developing the Image (continued) Figure 14: Writing the image and applying the toner