tailieunhanh - Lecture Introduction to Computers: Chapter 4A - Peter Norton's

Chapter 4A - Video and sound. This lesson introduces you to monitors and sound systems. You will learn about the different types of monitors commonly used with computers and how they work. You also w ill learn some important criteria for judging a monitor's performance. This lesson also shows you how computers can ourput sounds. | McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 4A Video and Sound Monitors Most common output device Connects to the video card Categorized by color output Monochrome One color with black background Grayscale Varying degrees of gray Color Display 4 to 16 million colors Monitors Cathode Ray Tube (CRT) Most common type of monitor Electrons fired from the back Electrons excite phosphor to glow Phosphor is arranged in dots called pixels Dot mask ensures proper pixel is lit Monitors CRT color Phosphor dots arranged in triads Red, green, and blue dots Three colors blend to make colors Varying the intensity creates new colors Teaching tip Unless your students have spend a lot of time with HTML or graphics colors, they will have a hard time grasping how RGB values work. The best methods are to show them various colors and then let them experiment. The website provides decimal-value examples of RGB values. Once the students have seen different colors, open MS Paint and let the students develop their own colors. Challenge them to build pink, orange, brown and any of their favorite colors Monitors CRT drawbacks Very large Very heavy Use a lot of electricity Monitors Liquid Crystal Display (LCD) Commonly found on laptops Desktop versions exist Solve the problems of CRT Fluorescent lights provide illumination Monitors Passive matrix LCD Pixels arranged in a grid Pixels are activated indirectly Row and column are activated Animation can be blurry Monitors Active matrix LCD Each pixel is activated directly Pixels have 4 transistors One each for red, green, blue One for opaqueness Transistors arranged in a thin film Animation is crisp and clean Monitors Drawbacks to LCD More expensive than CRT Must sit directly in front of screen Can be more fragile than CRT Insider information The limited viewing angle can be an advantage. For high security systems, low viewing angles stop casual glances at | McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. Chapter 4A Video and Sound Monitors Most common output device Connects to the video card Categorized by color output Monochrome One color with black background Grayscale Varying degrees of gray Color Display 4 to 16 million colors Monitors Cathode Ray Tube (CRT) Most common type of monitor Electrons fired from the back Electrons excite phosphor to glow Phosphor is arranged in dots called pixels Dot mask ensures proper pixel is lit Monitors CRT color Phosphor dots arranged in triads Red, green, and blue dots Three colors blend to make colors Varying the intensity creates new colors Teaching tip Unless your students have spend a lot of time with HTML or graphics colors, they will have a hard time grasping how RGB values work. The best methods are to show them various colors and then let them experiment. The website provides decimal-value examples of RGB .