Printers

1. Printers

2. Input: From Person to Processor

3. Output: From Pulses to People

4. In this project we will talk about one kind of output device : Printer

5. Paper Output (Printer) A computer printer, produces a hard copy (permanent human-readable text and/or graphics ) of documents stored in electronic form, usually on physical print media such as paper or transparencies.

6. Printer • The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine. • In 2007, a study revealed that toner-based printers produced pollution as harmful as that from cigarettes

7. Printer • Many printers are primarily used as local computer peripherals, and are attached by a printer cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces (typically wireless or Ethernet), and can serve as a hardcopy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time.

8. The First Printer Designer Charles Babbage (26 December 1791 – 18 October 1871) was an English mathematician, philosopher, and mechanical engineer .

9. Digitizing the Real World Scanners capture and digitize printed images Flatbed Slide Drum Sheet-fed

10. Fax Machines and Fax Modems • Facsimile (fax) machine • Sending: • fax machine scans each page as an image, • converts the image into a series of electronic pulses, • sends those signals over phone lines to another fax. • Receiving: • fax machine uses the signals to reconstruct the image and • print black-and-white facsimiles or copies of the originals • Fax modem: • directly from PC to fax machine via modem & phone line

11. Color Laser Printers Laser Printers Inkjet Printers Multifunction Printers Dot Matrix Printers Plotters Label Printers Line Printers photo Printers Refurbished Printers Portable Printers Card Printers Printers

12. Printers produce paper output or hard copy Two basic groups of printers: Impact printers nonimpact printers

13. Impact printers • Line printers • Dot-matrix printers • Generate output by striking the paper, ribbon, and print hammer together. • Uses an inked ribbon • Non-impact printers • Use methods other than force • Tend to be quiet and fast

14. Line printers - Impact printer - speedy but noisy - limited to printing characters.

15. Dot matrix printers • Impact printer • Used to print to multi-sheet pages • Print head strikes inked ribbon • Speed measured in characters per second

16. Dot Matrix Print Head

17. Non-impact printer • Inkjet printers • Sprays ink onto paper to produce printed text and graphic images • Prints fewer pages/minute than laser printer • High-quality color costing less than laser printer • Speed measured in pages per minute • Quality expressed as dots per inch

18. Dots Per Inch

19. High-Quality Printers • Photo printers • Produces film quality pictures • Prints very slow • Prints a variety of sizes

20. Multifunction printer or MFP combines a scanner, printer and a fax modem Plotter: an automated drawing tool that can produce large, finely scaled engineering blueprints and maps © 2006 Prentice-Hall, Inc.

21. Refrence • Computer Confluence • Introduction to computer • basics

22. How Things Work

23. How Things Work • Why does the paper always hot when they come out of the photocopier? The paper passes through the fuser which is a pair of heated rollers before coming out from the photocopier. The heat will melt the toner powder and the toner then fusing with the fibre of the paper. Finally, the finished copy is rolled to the output tray. The temperature of the finished copy will not be too hot because the speed of the paper rolling over the fuser is very fast, otherwise, it will burn up due to the high temperature of the fuser.

24. Inkjet Printer

25. Inkjet Printer • An inkjet printer is the printer that create image by placing extremely small droplets of ink onto paper. The dots are small, about 50-60 microns in diameter which is smaller than the diameter of human hair (70 microns). The resolution is about 1440 x 720 dots per inch (dpi). It may have different colours combining together to form a dot, creating photo-quality images. Inkjet printers have print head with 300 to 600 firing chambers which are tiny nozzles used to spray thousands of droplets of ink per second in a precise pattern to make up the text and images on a page. There are two types of inkjet technologies to squirt the ink droplets, thermal bubble printing technology and piezoelectric printing technology.

26. Thermal bubble printing • It uses heat to create a tiny bubble in the firing chamber forcing out an ink droplet. The printer heat a small quantity of ink by passing an electric current through a resistor. The temperature of ink reaches 900oF in a short time interval. The heating element vaporizes a tiny layer of ink for a few millionths of a second to create a bubble. Some of the ink is then pushed out of the nozzle. The whole process takes about 10 millionths of a second. The heating element cools down and the bubble collapses, creating suction that draws more ink into the print head from the ink cartridge. Each print head has many tiny nozzles that can fire ink droplets simultaneously.

27. Piezoelectric printing • It uses a piezoelectric crystal, which bends when an electrical current is applied to fire the ink drop onto the paper.

28. Piezoelectric printing • A piezoelectric crystal is located at the back of the ink reservoir of each nozzle. When an electrical current is applied, the crystal vibrates and changes its shape. • When the crystal vibrates inward, a tiny amount of ink is forced out of the nozzle. • When the crystal vibrates outward, deflects away from the chamber creating suction to pull more ink into the reservoir to replace the ink sprayed out. a

29. Piezoelectric printing • The advantage of this printing technology is that the quantity of ink in the droplet can be precisely controlled by adjusting the electric current applying on it. Larger current causes larger deflection producing larger droplets while smaller current produces little droplets. • The sequence of events taking place after you click OK button for printing: • The software application you are using sends the data to the printer driver through the connection interface (parallel, USB-UniversalSerialBus, etc). The printer driver translates the data into a format that the printer can understand and checks to see whether the printer is available to print or not. • The printer receives the data from the computer and stores a certain amount of data in a buffer. Storing data in a buffer allows the computer to finish the printing process quickly instead of having to wait for the actual page to print. • If the printer has been idle for a period of time, the printer will normally go through a short clean cycle to make sure the print head is clean and ready for printing

30. Piezoelectric printing • Paper feed stepper motor is activated to feed a sheet of paper from the paper tray into the printer by rollers. If there is no paper in the tray to depress the trigger, the printer lights up the "out of paper" LED and sends an alert to the computer. • Print head stepper motor uses a belt to move the print head assembly across the page once the paper is fed into the printer. The motor pauses for a fraction of a second each time that the print head sprays ink droplets on the page. Multiple dots can be made at each stop with precise amounts. This stepping happens in a fast speed that it seems like a continuous motion. • The process continues until the page is printed. The time it takes to print a page varies with the complexity of the page and the size of any images on the page. For example, a printer is able to print 16 pages per minute (PPM) of black text but takes several minutes to print a full colour page sized image. • The print head is parked after printing and the paper feed stepper motor spins the rollers to push the completed page into the output tray. Most printers use fast-drying inks so it is not necessary to wait for a long time before picking up the sheet.

31. Laser printer • Laser printer uses a laser beam to write letters or draw pictures on paper by sending data from the computer. What is the scientific principles using in the laser printing process? We will discuss this mystery in this section.

32. Laser printer

33. Laser printer • The principle used in a laser printer is static electricity. Initially, the photoreceptor drum is charged positively by corona wire by applying an electrical current on it. • Then the printer shines a tiny laser beam across the surface according to the data sent by the computer, one horizontal line at a time. The laser beam shines light on the drum for dot and light off for empty space on the page. The laser beam does not move itself but shines light through a movable mirror instead. The light discharge certain points on the photoreceptor drum and form an electrostatic image.

34. Laser printer

35. Laser printer • After the pattern is set, the toner stored in a toner hopper is gathered by the developer unit. The positively charged toner clings to the discharged areas of the drum but not to the positively charged background (area with no light shine on). • A sheet of paper (with strong negative charges) is moving along the belt and rolls over the drum with affixed toner powder pattern. The paper pulls the toner powder away from the drum and picks up the image pattern fixed by the fuser. Then the finished copy is rolled to the exit tray.

36. Comparison of laser printer with photocopier • Laser printers work the same basic way as photocopiers, with a few significant differences. • A photocopier scans an image by reflecting a bright light off of it, while a laser printer receives the image in digital form. • The electrostatic image is created by different ways: • For the photocopier, light bounces off a piece of paper and reflects back onto the photoreceptor from the white areas but is absorbed by the dark areas. The background is discharged. This method is called "write-white". • For the laser printer, the process is reversed. The laser discharges the lines of the electrostatic image and leaves the background charged. This method is called "write-black". • Medicine

37. Output: From Pulses to People • Multifunction printer or MFP combines a scanner, printer and a fax modem • Plotter: an automated drawing tool that can produce large, finely scaled engineering blueprints and maps

38. Supervised byOur TeacherMagda Al Sebai إعداد الطالبات شهد عبد العزيز الموح عهود سعد السيف أسما عبد الرحمن الغنام غاده داود الحوشان

39. Printers • Input: From Person to Processor Digitizing the Real World Fax Machines and Fax Modems Facsimile (fax) machine Output: From Pulses to People In this project we will talk about one kind of output device : Printer Fax modem: Paper Output (Printer) The First Printer Designer Charles Babbage

40. Printers Plotter: an automated drawing tool that can produce large, finely scaled engineering • Printers produce paper output or hard copy • Two basic groups of printers: • Impact printers • nonimpact printers Refrence Computer Confluence Introduction to computer basics • Impact printers • Line printers • Dot-matrix printers How Things Work Dot Matrix Print Head Dots Per Inch High-Quality Printers Photo printers • Produces film quality pictures • Prints very slow • Prints a variety of sizes

41. Printers • Inkjet Printer Comparison of laser printer with photocopier Laser printers work the same basic way as photocopiers, with a few significant differences Thermal bubble printing It uses a piezoelectric crystal, which bends when an electrical current is applied to fire the ink drop onto the paper Multifunction printer or MFP combines a scanner, printer and a fax modem Plotter: an automated drawing tool that can produce large, finely scaled engineering blueprints and maps Laser printer Laser printer uses a laser beam to write letters or draw pictures on paper by sending data from the computer. What is the scientific principles using in the laser printing process? We will discuss this mystery in this section.