Chapter 7 : Understanding Output

a) Output is data that has been processed into a useful form.

b) An output device is any type of hardware component that conveys information to one or more people.

Display Devices

• A display devices visually conveys text, graphics, and video information.
• A monitor is packaged as a separated peripheral
• LCD monitor
• Widescreen
• Liquid crystal display (LCD) uses a liquid compound to present information on a display device.
• Active-matrix display
• Passive-matrix display
• The quality of an LCD monitor or LCD screen depends primarily on:
• Resolution
• is the number of horizontal and vertical pixels in a display device.
• A higher resolution uses a greater number of pixels.
• Response time
• Brightness
• Dot pitch
• Contrast ratio
• The graphics processing unit (GPU) controls the manipulation and display of graphics on a display device.
• LCD monitors use a digital signal and should plug into a DVI port, an HDMI port, or a Display port.
• Plasma monitors are display devices that use gas plasma technology and offer screen sizes up to 150 inches.
•  Televisions also are a good output device.
• Require a convert if you are connecting your computer  to an analog television.
• Digital television (DTV) offers a crisper, higher-quality output. 
• HDTV is the most advanced form of digital television.
• A CRT monitor is a desktop monitor that contains a cathode-ray tube.
• Have a much larger footprint than do LCD monitors.

Printers

• A printer produces text and graphics on a physical medium.
1. Printed information is called a hard copy, or printout.
2. Landscape or portrait orientation.
• Various ways users print documents and photos :
1. Notebook  computer wirelessly communicates with system unit, which is connected to the printer on the home network.
2. Printer prints photos in camera when camera sits in docking station.
3. Printer prints image on memory card removed from camera and inserted in printer.
4. Smart phone communicates with printer wirelessly.
5. Digital camera communicates with printer wirelessly.
6. A non-impact printer  forms characters and graphics on a piece of paper without actually striking the paper.
• Ink-jet printers
• forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper.
• Color or black and white
• Printers with a higher dpi (dots per inch) produce a higher quality output.
• Photo printers
• produces color photo-lab-quality pictures
1. Most use ink -jet technology
2. PictBridge allows you to prit photos directly from a digital camera.
3. Print from a memory card and preview photos on a built-in LCD screen.
• Laser printers
1. High speed
2. Black and white
3. High quality
4. Color
• Thermal printers
• generates images by pushing electrically heated pins against the heat sensitive paper.
1. Thermal wax-transfer printer
2. Dye-sublimation printer
• Mobile printers
• is a small,lightweight, battery-powered printer that allows a mobile user to print form a notebook computer, smart phone, or other mobile device.
• Label and postage printers
1. A label printer is a small printer that prints on adhensive-type material.
2. A postage printer prints postage stamps
• Postage also can printed on other types of printers.
• Plotters
• are used to produce high quality drawings.
• Large format printers
• create photo-realistic quality color prints on a larger scale.

How a Black and White Laser Printer Works

1. Step 1: After the user sends an instruction to print a document, the drum rotates as gears and rollers feed a sheet of paper into the printer.
2. Step 2: A rotating mirror deflects a low powered laser beam across the surface of a drum.
3. Step 3: The laser beam creates a charge that causes toner to stick to the drum.
4. Step 4: As the drum continues to rotate and press against the paper, the toner transfer from the drum to the paper.
5. Step 5: A set rollers uses heat and pressure to fuse the toner permanently to the paper.
• A multifunction peripheral (MFP) is a single device that prints, scans, copies, and in some cases, faxes.
• Sometimes called an all in one device.
• Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper.
• Dot-matrix printer
• produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon.
• Line printer
• prints an entire line at a time.

Speakers, Headphones, and Earbuds

• An audio output device produces music, speech, or other sounds.
• Most computer users attach speakers to their computers to:
1. Generate higher quality sounds for playing games.
2. Interact with multimedia presentations.
3. Listen to music
4. View movies
• Headphones are speakers that cover or are placed outside of the ear.
• Earbuds (also called earphones) resit inside the ear canal.
• Some speakers are specifically designed to play audio from a portable media player.
• Wireless speakers
• Voice output occurs when you hear a person's voice or when the computer talks to you through the speakers.
1. Some Web sites dedicate themselves to providing voice output.
2. Often works with voice input.
3. VoIP uses voice output and voice input.

Other Output Devices

• are available for specific uses and applications
• Data projectors
• is a device that takes the text and images displaying on a computer screen and projects them on a larger screen.
• LCD projector
• Digital light processing (DLP) projector
• Interactive whiteboards
• is a touch sensitive device, resembling a dry-erase board, that displays the image on a connected computer screen.
• Force-feedback game controllers
• sends resistance to the device in a response to actions of the user.
• Tactile output
• provides the user with a physical response from the device