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