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Chapter 4AChapter 4A
Video and Sound
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MonitorsMonitorsMost common output deviceConnects to the video cardCategorized by color output
◦Monochrome One color with black background
◦Grayscale Varying degrees of gray
◦Color Display 4 to 16 million colors
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MonitorsMonitors
1. 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
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MonitorsMonitorsCRT color
◦Phosphor dots arranged in triads◦Red, green, and blue dots◦Three colors blend to make colors◦Varying the intensity creates new
colors
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MonitorsMonitorsCRT drawbacks
◦Very large ◦Very heavy◦Use a lot of electricity
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MonitorsMonitors
2. Liquid Crystal Display (LCD)◦Commonly found on laptops◦Desktop versions exist◦Solve the problems of CRT◦Fluorescent lights provide
illumination
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MonitorsMonitorsDrawbacks to LCD
◦More expensive than CRT◦Must sit directly in front of screen◦Can be more fragile than CRT
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MonitorsMonitors
3. Plasma monitor◦Gas is excited to produce light
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Monitors and Video CardsMonitors and Video CardsComparing Monitors:
1. Size2. Resolution3. Refresh rate4. Dot pitch
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Monitors and Video CardsMonitors and Video Cards
1. Size of monitor◦Measured in inches◦Actual size
Distance from corner to corner
◦Viewable size Useable portion of the screen
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Monitors and Video CardsMonitors and Video Cards
2. Resolution◦Number of pixels on the screen◦Higher number creates sharper
images◦Higher number creates smaller
images
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Monitors and Video CardsMonitors and Video Cards
3. Refresh rate◦Number of time the screen is redrawn◦Modern equipment sets this
automatically◦Improper settings can cause eyestrain
4. Dot pitch◦Distance between the same color dots
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Video CardsVideo CardsDevice between the CPU and monitorBetter cards result in better outputRemoves burden of drawing from
CPUHave their own processor and RAMModern cards have up to 512 MB
RAMCapable of rendering 3D images
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Data ProjectorsData ProjectorsReplaced overhead and slide
projectorsProject image onto wall or screenLCD projectors
◦Most common type of projector◦Small LCD screen◦Very bright light◦Require a darkened room
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Data ProjectorsData ProjectorsDigital Light Projectors
◦A series of mirrors control the display◦May be used in a lighted room
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Sound SystemsSound Systems• Integral part of the computer
experienceCapable of recording and
playback
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Sound SystemsSound SystemsSound card
◦Device between the CPU and speakers
◦Converts digital sounds to analog◦Can be connected to several devices
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Sound SystemsSound SystemsHeadphones and headsets
◦Replacement for speakers and microphones
◦Offer privacy◦Does not annoy other people◦Outside noise is not a factor◦Headsets have speakers and a
microphone
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Chapter 4BChapter 4B
Printing
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Commonly Used PrintersCommonly Used PrintersImpact printers
◦Generate output by striking the paper
◦Uses an inked ribbon Non-impact printers
◦Use methods other than force◦Tend to be quiet and fast
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Commonly Used PrintersCommonly Used Printers
1. Dot matrix printers◦Impact printer◦Used to print to multi-sheet pages◦Line printers◦Band printers◦Speed measured in characters per
second
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Dot Matrix Print HeadDot Matrix Print Head
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Commonly Used PrintersCommonly Used Printers
2. Ink-jet printers◦Non-impact printer◦Inexpensive home printer◦Color output common using CMYK
Cyan, magenta, yellow, black
◦Sprays ink onto paper◦Speed measured in pages per
minute◦Quality expressed as dots per inch
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Dots Per InchDots Per Inch
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Commonly Used PrintersCommonly Used Printers
3. Laser printer◦Non-impact printer◦Produces high quality documents◦Color or black and white◦Speed measured in pages per
minute◦Quality expressed as dots per inch
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Commonly Used PrintersCommonly Used Printers
4. All-in-one peripherals◦Scanner, copier, printer and fax◦Popular in home offices◦Prices are very reasonable
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Comparing PrintersComparing PrintersDetermine what you needDetermine what you can spendInitial costCost of operatingImage qualitySpeed
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High-Quality PrintersHigh-Quality Printers
1. Special purpose printers◦Used by a print shop◦Output is professional grade◦Prints to a variety of surfaces
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High-Quality PrintersHigh-Quality Printers
2. Photo printers◦Produces film quality pictures◦Prints very slow◦Prints a variety of sizes
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High-Quality PrintersHigh-Quality Printers
3. Thermal wax printers◦Produces bold color output◦Color generated by melting wax◦Colors do not bleed ◦Operation costs are low◦Output is slow
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High-Quality PrintersHigh-Quality Printers
4. Dye sublimation printers◦Produces realistic output◦Very high quality◦Color is produced by evaporating ink◦Operation costs are high◦Output is very slow
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High-Quality PrintersHigh-Quality Printers
5. Plotters◦Large high quality blueprints◦Older models draw with pens◦Operational costs are low◦Output is very slow
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Chapter 4Chapter 4
End of Chapter
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