Bulbul NUB 1. Outline. Week # 02. Standard Input & Output Devices. Input Device 6/3/2018

Transcription

1 Standard Input & Output Devices June 3, 2018 Week # 02 Course: Introduction to Computers Course Code: CIT1101 Presented by: Bulbul Ahamed Assistant Professor of CSE, NUB Bulbul Ahamed 1 Definition of Input Device Keyboard, Mouse, Trackball Touchpad, Microphone Digital Camera, Web Cam Scanners, Bar Code Reader OMR, OCR Definition of Output Device Types of Output Monitor, Printer, Speaker, Projector Outline 2 Enter data to be processed Input Devices Input Device An input device is any hardware component that allows users to enter data and instructions into a computer. Examples: Keyboard Mouse Trackball Touchpad Microphone Digital Camera Web Cam Scanner Bar Code Readers OMR OCR 3 4 Bulbul Ah@med, NUB 1

2 Keyboard The most common input device, used to enter letters, numbers, symbols, punctuation and commands into the computer. A standard computer keyboard has 101 keys; each key sends a different signal to the CPU. 5 Keyboard (Cont ) IBM computers has 101 keys. They are arranged in five groups: Alphanumeric keys: A-Z, 0-9, Symbols (#, &, % etc), Enter, Backspace, Caps Lock, Tab, Spacebar etc. Modifier Keys: Shift, Ctrl, Alt Numeric Keypad: Num Lock, 0-9, /, *, -, + Function Key: F1-F12 Cursor-Movement Keys: Arrows (Up, Down, Left, Right), Insert, Home, Page up, Delete, End, Page Down, Print Screen Sys Rq, Scroll Lock, Pause Break Special-Purpose Keys: Start, Shortcut 6 Keyboard (Cont ) Mouse A mouse is a hand-movable input device that controls the position of the cursor or pointer on a screen. Commonly used with desktop computers Frequently one can upgrade the mouse 2 button with wheels Optical Mouse.. no trackballs! Wireless Mouse no tail! 7 8 Bulbul Ah@med, NUB 2

3 Configuration of a Mouse Trackball A trackball is a pointing device with a ball on its top or side. Wheel Right Button Left Button The onscreen pointer is moved by the trackball with a thumb or finger. Most trackballs feature two buttons, although three button models are also available. Trackballs are used frequently with laptop computers. 10 Touchpad A pressure-sensitive input device used to control the on-screen pointer by moving the fingertips over the pad's surface. Used especially on laptop computers as an alternative to a mouse. It has two or three buttons that perform the same functions as mouse buttons. Microphones - Speech Recognition Use a microphone to talk to your computer Add a sound card to your computer Sound card digitizes audio input into 0/1s A speech recognition program can process the input and convert it into machinerecognized commands or input Bulbul Ah@med, NUB 3

4 Digital Camera A digital camera (or digicam for short) is a camera that allows users to take pictures or video digitally, instead of on traditional film. Used to record images that can be viewed and edited on a computer. Web Cam Webcams are video capturing devices connected to computers or computer networks. A Web cam or Web camera connected to a computer or server that allows anyone connected to the Internet to view still pictures or motion video of a user **A PC Equipped with a Computer Camera Scanners An optical scanner, usually called scanner, is a light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can process Bulbul Ah@med, NUB 4

5 Scanners (Cont ) Optical Reader An optical reader is a device that uses light source to read characters, marks, and codes and then convert them into digital data that a computer can process. Image Scan Edit Optical Character Reader (OCR) Optical Mark Reader (OMR) Bar Code Reader Bar Code A bar code is made up of vertical printed lines (bars) and spaces. The sequence of bars and spaces of different thickness represents a sequence of numbers. Bar Code Readers (Cont ) Bar Code Reader also called a bar code scanner, is an optical reader that uses laser beams to read bar codes by using light patterns that pass through the bar code lines Bulbul Ah@med, NUB 5

6 Optical Mark Reader Optical Mark Reader (Cont ) OMR is a special scanning device that reads hand drawn marks such as small circles or rectangles on specially designed documents. Example: The OMR device scans the answer key sheet to record correct answers based on patterns of light. Use lead pencil to mark on scan sheet Feed the scan sheets into the OMR Where do we use OMR? School registration Lottery Tickets Some questionnaires Multiple choice examinations Optical Character Recognition OCR technology that enables a computer translate optically scanned text into character codes, that you can edit. OCR software can be installed in a computer to perform character recognition. to Bulbul Ah@med, NUB 6

7 Bulbul NUB 7 6/3/2018 Optical Character Recognition (Cont ) Definition of Output Device An output device is any type of hardware component that conveys information to one or more people. A device, such as a printer, video display, or speaker, that presents data from a computer to a user Jun-18 Bulbul Ahamed 26 Types of Output Hard Copy: A hard copy (or "hardcopy") is a printed copy of information from a computer. Example: Printer output Soft Copy: A soft copy (or "softcopy") is an electronic copy of some type of data, such as a file viewed on a computer's display or transmitted as an attachment. Monitor display screens Loudspeaker output Examples of Output Devices Monitor Projector Printer Plotter Speaker 3-Jun-18 Bulbul Ahamed 27 3-Jun-18 Bulbul Ahamed 28

8 Monitor Types of computer monitor A monitor (sometimes called a visual display unit) is a display device or simply display, is an output device that visually conveys text, graphics, and video information. CRT (Cathode Ray Tube) LCD (Liquid Crystal Display) LED (Light-Emitting Diodes) 3-Jun-18 Bulbul Ahamed 29 3-Jun-18 Bulbul Ahamed 30 Cathode Ray Tube (CRT) CRT monitors were the only choice consumers had for monitor technology for many years. Cathode ray tube (CRT) technology has been in use for more than 100 years, and is found in most televisions and computer monitors. Features of LCD monitors include: Bulky, heavy, use vacuum tube technology Produce more heat Inexpensive (Low cost) High power consumption Liquid Crystal Display (LCD) An LCD monitor, called a flat panel monitor, is a desktop monitor that uses a liquid crystal display to produce images. Features of LCD monitors include: Lighter weight More compact (Thin) Expensive Take up less space Low power consumption Produce less heat Sharp Picture, Flicker-free image 3-Jun-18 Bulbul Ahamed 31 3-Jun-18 Bulbul Ahamed 32 Bulbul Ah@med, NUB 8

9 Bulbul NUB 9 6/3/2018 Light-emitting Diode (LED) LED monitors are the latest types of monitors in the market today. Like LCD, it is again a flat panel display making use of light-emitting diodes for back-lightning instead of Cold Cathode Fluorescent (CCFL) back-lightning used inlcds. Features of LED monitors include: Produce images with higher contrast Less negative environmental impact when disposed Lifespan and durability of LED monitors is more than CRT and LED monitors Very thin and do not use much heat Better viewing angles than LCD monitors Definition of Printer A printer is an output device that produces text and graphics on a physical medium such as paper or transparency film. Printed information is called hard copy. It can be connected directly to the computer or indirectly via a network. 3-Jun-18 Bulbul Ahamed 33 3-Jun-18 Bulbul Ahamed 34 Examples of Printer Line Printer Laser Printer Line Printer A line printer is a high-speed impact printer that prints an entire line at a time. Printing Speed: Usually 400-2,000 lines per minute (lpm) Commonly found in datacenters and industrial environment 3-Jun-18 Bulbul Ahamed 35 3-Jun-18 Bulbul Ahamed 36

10 Laser Printer A laser printer is a high speed, high quality nonimpact printer. A laser is at the heart of this printer that uses technology similar to in photocopiers Laser Printer (Cont ) Prints one page at a time dpi High quality Speed Personal laser printers: 8-10 ppm Network laser printers: ppm High-volume laser printers: up to 1000 ppm ppm: pages per minute dpi: dots per inch 3-Jun-18 Bulbul Ahamed 37 3-Jun-18 Bulbul Ahamed 38 Speaker A speaker is an output device that converts electrical signals into sound waves. A sound card translates digital sounds into the electric current that is sent to the speakers. Allow the digital sound to be heard Best choice for games and videos Projector A device that projects computer output onto a larger screen or wall. It is widely used in classrooms and auditoriums for instruction and slide presentations. Some people getting them for home theatre systems 3-Jun-18 Bulbul Ahamed 39 3-Jun-18 Bulbul Ahamed 40 Bulbul Ah@med, NUB 10

11 Bulbul NUB 11 6/3/2018 Thanks for your Attention!! Any Questions? 41