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LECTURE_06

Introduction to Computing

  • Course: CSC 101

  • Lecture 6 by Kashif Iqbal

  • Contact: Kashif.iqbal@zu.edu.pk

Last Lecture Summary

Ergonomics and Input Devices

  • Discussed Repetitive Stress Injuries (RSIs)

  • Explored Carpal Tunnel Syndrome and prevention tips

  • Techniques to avoid keyboard-related injuries

  • Proper sitting posture at a computer

Alternate Input Devices

  • Devices for the hand:

    • Pen, Touch Screens

    • Game controllers: Joystick, Game Pad

  • Optical Input Devices:

    • Bar Code Reader, Image Scanners, OCR

  • Audio Input Devices:

    • Microphone, Sound Card, MIDI

  • Video Input Devices:

    • Video Camera, Webcam, Digital Camera

Output Devices

  • Early output devices (pre-1960s) were uncommon

  • Modern capabilities:

    • Various methods of communicating information: reading, seeing, watching, listening

  • Improvements in display and sound systems:

    • Enhanced ease of use, data management, and access to information

Monitors

Types of Monitors

  • Two primary types:

    • Cathode Ray Tube (CRT)

    • Flat-panel monitors

Characteristics of Monitors

  • Categorized by color output:

    • Monochrome: one color on a black background

    • Grayscale: varying degrees of gray

    • Color: capable of displaying 4 to 16 million colors

CRT Monitors

Image Creation

  • Electron gun shoots streams of electrons onto the screen

  • Magnetic yoke guides the electron streams across the screen

  • Phosphor dots glow upon electron impact

Components of CRT

  • Cathode, electron beam, accelerating anodes, deflection coils, phosphorescent screen

Color Representation

  • Arrangement of phosphor dots: red, green, blue

  • Blending colors through varying intensity

Disadvantages of CRT

  • Large, heavy, and high electricity consumption

Liquid Crystal Displays (LCD)

Overview

  • Commonly found in laptops and desktops

  • Resolution of CRT issues with use of fluorescent lights

Types of LCD

  • Passive Matrix LCD

    • Indirect pixel activation

    • Limited viewing angles and slower refresh rates

  • Active Matrix LCD

    • Direct pixel activation via transistors

    • Clear and crisp animation due to thin-film transistors (TFT)

Drawbacks of LCD

  • Difficult visibility in bright light

  • Smaller viewing angles and fragility

Alternative Display Technologies

Types

  • Plasma Display Panel (PDP):

    • Small cells filled with ionized gases

    • Pros: superior picture quality and wider viewing angles

    • Cons: screen burn-in and higher power usage

Light Emitting Diodes (LED)

  • Greater dynamic contrast and slim design

  • Lower power consumption and less environmental impact

Additional Monitor Types

  • Paper-white displays: high contrast

  • Electro-luminescent displays: similar to LCD

Comparing Monitors

Evaluation Criteria

  • Size, resolution, refresh rate, dot pitch

  • Importance of image clarity and adjustable controls for user effectiveness

Size of Monitor

  • Measured diagonally; choose the largest affordable size

Resolution

  • Higher pixel count yields sharper and clearer images

Refresh Rate

  • Frequency of screen redraw, impacting eyestrain

Dot Pitch

  • Distance between same color dots; smaller dot pitches provide finer images

Video Cards

Functionality

  • Interface between CPU and monitor providing better output

  • Alleviates CPU workload and includes dedicated RAM

Capabilities

  • Modern cards with up to 8GB VRAM, capable of 3D rendering

  • Examples: ATI’s Radeon, NVIDIA’s GeForce

Ergonomics and Monitors

Eyestrain Prevention

  • Measures include proper monitor choice and positioning

    • Recommended distance: 2-3 feet

    • Center of the screen below eye level

Electronic Magnetic Field (EMF)

Health Considerations

  • EMF produced by electronic devices may pose health risks

  • Recommendations: keep the device at arm's length, take breaks, use LCDs

Data Projectors

Usage

  • Replaced older projectors; projects images onto surfaces

  • Most common type: LCD projectors with bright light requirements

Sound Systems

Integration

  • Essential for sound functionality in computing experiences

  • Capable of managing both recording and playback

Sound Cards

  • Devices converting digital to analog sound for speakers

  • Support features like Dolby Surround Sound

Headphones and Headsets

  • Alternatives to speakers, offering privacy and reduced noise interference

Summary

Key Topics Covered

  • Output Devices: Monitors, different types (CRT, LCD, PDP)

  • Comparison aspects: Size, resolution, refresh rate, dot pitch

  • Video Cards and their role

  • Ergonomics considerations related to monitor use

  • Overview of Electronic Magnetic Field concerns

  • Data projectors and sound system integration

Recommended Websites

  • http://www.lynda.com/resources/hexpalette/hue.html

  • https://en.wikipedia.org/wiki/Plasma_display

  • https://en.wikipedia.org/wiki/LED_display

  • https://en.wikipedia.org/wiki/Video_card

  • http://www.tech-faq.com/how-lcd-projectors-work.html