Peripheral devices Input devices

1. Peripheral devicesInput devices

2. Input Devices • Input devices, such as keyboards or scanners, are hardware components that capture, collect, and transmit data and programs to the computer in a form that computer can understand. • Input devices transmit the input to the computer in a series of electronic pulses representing bits, or digits, of the binary code.

3. Types of Input • Data • raw facts that a computer receives and processes to produce information • Programs • instructions that direct the computer operations • Commands • key words that direct the computer to perform certain activities • User Responses • data a user enters to respond to a question or message.

4. Different type of input devices • A. Keyboard • B. Pointing devices • C. Pen input devices • D. Scanning devices • E. Multimedia input devices

5. Function key Numeric keypad A. Keyboard • The most commonly used input devices. • Contains alphanumeric, cursors and function keys.

6. Function Keys, labeled from F1 to F12, allow user to quickly access commands and functions, such as saving a document or calling up a program’s Help feature. • Cursor-control Keys govern the movement of the cursor on the screen. They include Up Arrow, Down Arrow, Left Arrow and Right Arrow key on the keyboard. • Special Purpose Keys are used in conjunction with other keys to enter commands into a computer. Control (Ctrl), Alternate (Alt) Windows and Shift keys are example of special purpose keys.

7. Toggle Keys are keys that, when pressed, activates a certain mode or condition, and when pressed again, deactivates the condition. The Num Lock key, Cap Lock key and the Scroll Lock key are examples of toggle keys. (For example, pressing the Cap Lock key will cause all the alphanumeric characters to appear in capitals without holding down the Shift key.) • Numeric Keypad, located in the far right portion of the keyboard, is used for entering numbers quickly and for performing the same operations as a calculator. Not all keyboards have the same layout. Most keyboards have adopted the so-called QWERTY layout for the alphanumeric keys.

8. 104-key keyboard Natural keyboard Keyboard for the Mac Types of Keyboard

9. B. Pointing Devices • Many people use pointing devices instead of keyboards whenever possible. • Pointing devices minimize the amount of typing (and the number of errors).

10. Mouse • Palm-sized pointing devices • a ball on the bottom senses its movement • various actions can be preformed by moving the pointer and then pressing one of the buttons on top of the mouse.

11. Cordless wheel mouse 3-button mouse iMouse for iMac Wheel mouse for notebooks Types of Mouse

12. Serial PS2 USB Mouse Interfaces

13. Trackball • Up-side down mouse • user rotates the ball itself while clicking nearby buttons

14. TrackPoint Touchpad • The mouse is not practical for people using a notebook computer in a small space. Track Point or Touch pad is therefore used instead to control the pointer.

15. A touch screen kit solution Touch-Sensitive Screens • Touch screens enable the user to select an option by pressing a specific part of the screen. • Touch screens are commonly used in grocery stores(食品雜貨店 ), fast-food restaurants, and information kiosks.

16. Joysticks • Use the movement of a vertical stem to direct the pointer.

17. C. Pen Input Devices • Input data with hand written characters, select items by pressing the pen against the screen, and use gestures, which are special symbols, to issue commands.

18. Light Pen • Used to select processing options or to draw on the screen The tip of a light pen contains a highly sensitive photoelectric cell. When the light pen is pointed close to the screen, the photoelectric cell detects the light emitted from the exact spot the pen is touching. This accuracy makes light pens very popular among engineers and draftsmen who use computer-aided design (CAD) software to create blueprints and drawings of products or construction projects.

19. Digitizing Tablet • A digitizing tablet consists of a grid on which designs and drawings can be entered. • Most tablets are pressure-sensitive, and the user draws directly on the tablet using a special pen called a stylus. Digitizing tablets are used to design cars, buildings, medical devices, and robots.

20. Chinese Handwriting Recognition Device • Used for inputting and recognizing Chinese handwriting Nowadays, sophisticated(尖端的)Chinese handwriting recognition system also contains voice recognition function.

21. D. Scanning Devices

22. Image Scanner • Electronically capture an entire image & convert it into digital form that can be processed by a computer

23. Scan Edit Image

24. An example of a bar code Bar Code Reader • Bar code consists of a set of vertical lines and spaces of different widths • Universal Product Code (UPC) is very common

25. Magnetic Ink Character Magnetic Ink Character Recognition (MICR) • Use a special ink that can be magnetized during processing • MICR is used by the banking industry as a means of processing checks it receives in every day.

26. Optical Character Recognition a system of producing machine-readable code on a data source item and reading that code by means of optical scanning devices. • OCR software can be installed in a computer to perform character recognition.

27. Use lead pencil to mark on scan sheet Feed the scan sheets into the OMR Optical Mark Recognition • Optical marks are the filled-in shape, usually ovals or rectangles, on scan sheets. • The data collected on the scan sheets are translated into binary form by an optical mark reader (OMR)

28. E. Multimedia Input Devices

29. Voice Input Devices • A voice input device has two functions: • First, it can simply record and play back the voice inputted by the user. • Secondly, it can record a human voice, then with appropriate voice recognition software, convert the voice input to ASCII characters.

30. View Cam Digital Camera • Record images in a form that can be stored by a computer. • Some digital cameras resemble traditional cameras and are portable. Some are connected directly to a computer.