1 / 31

Using Information Technology

Using Information Technology Chapter 5 Hardware: Outside the box Expected outcome after this lecture After this lecture, students are expected to be able to: Give examples on different types of Input and Output devices Understand how mechanical and optical mouse works

Renfred
Download Presentation

Using Information Technology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Using Information Technology Chapter 5 Hardware: Outside the box

  2. Expected outcome after this lecture After this lecture, students are expected to be able to: • Give examples on different types of Input and Output devices • Understand how mechanical and optical mouse works • Discuss the advantages and features provided by different types of scanners (handheld v.s. flatbed) • Explain how CRT monitor and LCD monitor works and compare their relative advantages • Perform simple calculation on display memory • Explain the different attributes of a monitor (resolution, color depth, dot pitch, refresh rate…) • Compare the mechanism and advantages of different types of printers

  3. Input device • Device that translate human readable data into data which can be understand and process by computer • 3 types: • Keyboard type devices – converts characters into computer readable form • Pointing devices – control the position of cursor or pointer on the screen • Source data-entry devices – converts other form of data into computer readable form

  4. How to get input from keyboard? • When a key is pressed, the scan code is generated and the character will be stored in buffer for further process. • Information is sent to PC via PS/2 or USB port • Wireless interface is becoming more common

  5. Different types of keyboards 101 Keyboard - Total 101 keys 104 Keyboard (for Win) - With Start Menu/Menu keys Ergonomic Keyboards -Reduce fatigue

  6. The future… Virtual Laser Keyboard Senseboard Virtual Keyboard

  7. First Mouse - by Doug Engelbart in 1968

  8. Mechanical Mouse Use a rubber ball to detect motion Inside the socket, there are 2 rollers arranged at 90o A Roller moves a wheel with holes The wheel block/unblock the light of Infrared LED emitter/receiver, hence enable the detection of speed

  9. Optical Mouse • No ball / wheel • Work on almost all surfaces • LED at the bottom emits light to surface • Light rebound and is captured by sensor • (Taking 1500 pictures per second) • Pictures are sent to Digital Signal Processor (DSP) to detect the motion

  10. Multi-touch • Multi-touch technology is becoming more and more common nowadays • Apart from specifying position(s) as in typical pointing devices and touch-screen, multi-touch supports “Gestures” which is mapped to operations like zoom, reload, flip page…etc

  11. In the News: Microsoft-Surface • Computer from MS, supporting multi-touch gesture, multi-user interaction and object recognition. • Possibilities: • Project/Games with multi-users • Information counters (e.g. showing maps, menus..etc) • Art / Entertainment (draw picture with a “real” brush?) • Interaction with other hand-held devices…etc. • http://www.youtube.com/watch?v=rP5y7yp06n0

  12. Source data-entry devices • No keystroke is required to input data • Data is entered directly from the source and translated into digital format • Bar-code reader • Digital camera • Fax machine • Image scanner • Voice recognition • Biometric scanner (e.g. fingerprint)

  13. Biometric scanners

  14. Scanner • Handheld scanner • Rely on the user to move • Poor image quality • Flatbed scanner • Light and sensor moved by motorized belt. • Additional Features • Scanning of photographic negatives • Auto Document Feeder • Software: Denoise, OCR (Optical Character Recognition)

  15. Output device • Device that translate information processed by computer into human readable form • Two Types: • Hardcopy • In a printed form • Printer, plotter, microfilm, microfiche

  16. Output devices • Softcopy • Display on screen, voice output, sound output, video output, mechanical output

  17. Display screens • Monitor, Cathode-Ray Tube (CRT) • A vacuum tube (chamber) used as a display screen • The screen of a CRT is filled with Red/Green/Blue phosphor dots / pixels (picture element) • A CRT works by moving an electron beam back and forth across the back of the screen • When the beam pass across the screen, it lights up phosphor dots • Fast response time • Images are clear and bright • Big, heavy and consume more power

  18. LCD – liquid crystal display • Light shine through a layer of crystalline liquid to make an image • Relatively Thinner and lighter • Low power consumption (only 1/3 of CRT) • Images might not be clearly viewed from an angle • Usually has longer response time and yields “motion blur”

  19. How fine your display can be? • Screen size (diagonal length measured in inch) • Resolution • A measure of the number of pixels used for the whole screen • Determines the fineness of display details • 640480, 800600, 1024768, etc. • Color depth • Number of possible colors for each pixel • 256 color (8 bits), High color (16 bits), True color (24 bits)

  20. Calculation on the number of pixels • For 1280x1024 display, total number of pixels= 1280x1024 = 1310720 pixels = 1.3 Mega pixels • Assume the display uses True Color (24 bits) • Each pixel consumes: 24bits = 24/8 = 3 bytes • Total display memory = 1310720 x 3 = 4MB memory

  21. Dot pitch • Amount of space between the centers of adjacent pixels • Smaller space  closer pixels finer image • Refresh rate • Number of times per second that the screen get refreshed • Pixels are recharged to remains bright • Higher refresh rate  More solid image • 60 Hz (1 second refresh 60 times)

  22. The future… • 3D LCD monitor by Toshiba

  23. Printers • Impact printer / Dot-matrix printer • Direct physical contact between printing mechanism and paper • Similar to a mechanical typewriter • 9 (low quality), 18 or 24 pins (best quality) • Noisy and slow • Still used nowadays to create “carbon copy” in Multi-Layered forms.

  24. Non-impact printer • Without direct physical contact • Faster and quieter than impact printer • Ink-jet printers • Print head contains nozzles that are used to spray drops of ink • Heat (Bubble Jet by Canon, HP) vs Vibration (Epson) • 4 (common) or 6 colors • 4 colors – CMYK: Cyan, Magenta, Yellow, Black • 6 colors – CcMmYK: Cyan, cyan, Magenta, magenta, Yellow, Black

  25. Four primary colors for printing - CMYK

  26. Laser printer • Better quality and more expensive • Fire a laser beam on paper? • An electrostatic process (static electricity) • Black color or 4 colors (CMYK) • Fast printing speed (up to 35 ppm) • May be slower for color (8 ppm)

  27. Printing with laser printer

  28. Printer qualities • Color • Resolution • The sharpness of text and images on paper • Measured in dots per inch (dpi) • Dot Matrix = 72-144, Ink Jet = 300-2400, Laser = 600-2400 • Speed • Measured in characters per second (cps) or pages per minute (ppm) • Memory • A buffer holding the information waiting to be printed • More memory faster printing (8-32MB, up to 416MB)

  29. Comparison on color laser v.s. ink jet • Problems of color ink jet: • Need high quality paper to prevent ink from feathering • Picture is less precise than color laser • Slow (high quality printing in ink jet may takes 10 mins) • Need to wait for a freshly printed page to dry • Ink-jet cartridges are more expensive than laser toner (Although the printer itself is cheaper)

  30. All-in-one Printer/Scanner/Fax • Nowadays, some printer firms (e.g. Hewlett-Packard) manufactures various models of all-in-one machines, which combines the functions of scanner, printer and modem • Scanner + Printer = Photo-copier • Scanner + Modem = Fax transmitter • Modem + Printer = Fax receiver

  31. Readings • “Using Information Technology”, Ch 6 • http://computer.howstuffworks.com • http://computer.howstuffworks.com/mouse2.htm • http://www.viewsonic.com/monitoruniversity/lcd.htm

More Related