1. Introduction to Computers
Section 3A
Introduction to Computers

2. Two Kinds of Monitors Cathode ray tube (CRT) Flat-panel display
Monitors are categorized by the technology they use
CRT Monitors
In CRT monitors, electrons are fired at phosphor dots on the screen.
The dots are grouped into pixels, which glow when struck by electrons.
In color CRTs, each pixel contains a red, green, and blue dot. These glow at varying intensities to produce color images.
Flat Panel Display
Most flat-panel monitors use liquid crystal display (LCD) technology.
Passive matrix LCD uses a transistor for each row and column of pixels.
Active matrix LCD uses a transistor for each pixel on the screen.
Thin-film transistor displays use multiple transistors for each pixel.

3. Monitor Categories Based on Color Display
Monochrome: One color on a black background
Grayscale: Shades of gray on a white or off-white background
Color: From 16 to 16 million unique colors

4. Pixel
Pixel, short for picture element, is the smallest number of phosphor dots that the electron gun inside the monitor can focus on

5. Shadow mask
A fine mesh made of metal and fitted to the shape and size of the screen

6. Liquid Crystal Display (LCD) Monitor
Most common flat-panel monitor

7. Viewing Angle
The angle from which the display’s image can be viewed clearly

8. Two Categories of Liquid Crystal Displays
Passive matrix LCD
Active matrix LCD

9. Other Kinds of Monitors
Paper-white display
Electroluminescent (ELD) display
Plasma/gas plasma display
Paper-white displays – Produce a very high contrast between the monitor’s white background and text or graphics. They are used to create high-quality printed documents.
Electroluminescent (ELD) displays – Use a phosphorescent film held between two sheets of glass.
Plasma/gas plasma displays – Created by sandwiching a special gas between two sheets of glass.

10. Considerations When Monitor Shopping
Size
Resolution
Refresh rate
Dot pitch

11. Video Controller Intermediary device between the CPU and the monitor
Controls how things look on-screen
The video controller is an interface between the monitor and the CPU.
The video controller determines many aspects of a monitor's performance, such as resolution or the number of colors displayed.
The video controller contains its own on-board processor and memory, called video RAM (VRAM).

12. Digital Light Projector
Connects to a computer and is used to project images on a large screen
Many digital light projectors provide the same resolutions and color levels as high-quality monitors.
Digital light processing (DLP) projectors use a microchip containing tiny mirrors to produce very sharp, bright images.

13. Sound Card
Translates digital sounds into the electric current that is sent to the speakers
Sound Cards
Multimedia PCs come with a sound card, speakers, and a CD-ROM or DVD drive.
A sound card translates digital signals into analog ones that drive the speakers.
With the right software, you can use your PC to edit sounds and create special sound effects.
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14. Monitors and Sound Systems
Section 3A
Monitors and Sound Systems