Assignment Chapter 6 From Mr Tri Djoko Wahjono

ASSINGNMENT CHAPTER 6

Chapter Review Pages 332 – 333

Discovering Computer (“Living In the Digital World 2011”)

Lecture       :        Mr. Tri Djoko Wahjono

Student      :        Williem [1701309721]

1. What are the four types of output?

Output is data that has been processed into a useful form That is, computers process data (input) into information (output). The form of output varies, depending on the hardware and software being used and the requirements of the user. Monitors, traditional notebook computers, netbooks, Tablet PCs, portable media players, smart phones, digital cameras, and other mobile devices have screens that allow users to view documents, Web sites, e-mail messages, photos, videos, and movies. Many printers enable users to print color documents and photos. Through the computer’s speakers, headphones, or earbuds, users listen to sounds, music, and voice messages.

While working with a computer, a user encounters four basic types of output: text, graphics, audio, and video. Very often, a single form of output, such as a Web page, includes more than one of these types of output.

·         -Text: examples of output that primarily contain text are memos, letters, press releases, reports, classified advertisements, envelopes, mailing labels, and text messages. On the Web, users view and print many other types of text-based output. These include blogs, news and magazine articles, books, television show transcripts, stock quotes, speeches, and lectures.

·         -Graphics: many forms of output include graphics to enhance visual appeal and convey information. Business letters have logos. Reports include charts. Newsletters use drawings, clip art, and photos. Users print high-quality photos taken with a digital camera. Many Web sites use animated graphics, such as blinking icons, scrolling messages, or simulations.

·         -Audio: Users download their favorite songs from iTunes and listen to the music while working on the computer. Software such as games, encyclopedias, and simulations often have musical accompaniments for entertainment and audio clips, such as narrations and speeches, to enhance understanding. On the Web, users tune into radio and television stations and listen to audio clips, podcasts, or live broadcasts of interviews, talk shows, sporting events, news, music, and concerts. They also use the Internet to conduct real-time conversations with friends, coworkers, or family members, just as if they were speaking on the telephone.

·         -Video: as with audio, software and web sites often include video clips to enhance understanding. Vodcasts and video blogs, for example, add a video component to the traditional podcast and blog. Users watch a live or prerecorded news report, view a reply while attending a live sporting event, observe weather conditions, or enjoy a live performance of their favorite musician or musical group on a computer or mobile device. Instead of renting a movie, users can download movie content from a Web site for a fee and then watch the entire movie on a computer or mobile device. Attaching a video camera to the computer allows users to watch home movies on the computer. They also can attach a television’s antenna or cable to the computer and watch a television program on the computer screen.

2. What are the characteristics of various display devices?

A display device, or simply display, is an output device that visually conveys text, graphics, and video information. Information on a display device, sometimes called soft copy, exists electronically and appears for a temporary period.

Display devices consist of a screen and the components that produce the information on the screen. Desktop computers typically use a monitor as their display device. A monitor is a display device that is packaged as a separate peripheral. Some monitors have a tile-and-swivel base that allows users to adjust the angle of the screen to minimize neck strain and reduce glare from overhead lightning. With some, you can rotate the screen. Adjustable monitor stands allow you to adjust the height of the monitor. Monitor controls permit users to adjust the brightness, contrast, positioning, height, and width of images. Some have integrated speakers and/or a build-in Web cam.

Most mobile computers and devices integrate the display and other components into the same physical case. Some have touch screens. Traditional notebook computers and netbooks have a display that attaches with a hinge to the system unit. Tablet PCs are available with two types of displays: one that attaches with a hinge and one built into the top of the case. Some smart phone and digital camera displays also attach with a hinge to the device. On other smart phones and most PDAs, portable media players, digital cameras, and handheld game consoles, the display is built into the case. Newer vehicles integrate a display in the dashboard, enabling drivers to control audio, video, navigation, temperature, and other settings. Most display devices show text, graphics, and video information in color. Some, however are monochrome. Monochrome means the information appears in one color (such as white, amber, green, black, blue, or gray) on a different color background (such as black or grayish-white). Some mobile devices use monochrome displays because they require less battery power.

Two types of display devices are flat-panel displays and CRT monitors. A flat-panel display is a lightweight display device with a shallow depth and flat screen that typically uses LCD (liquid crystal display) or gas plasma technology. Types of flat-panel displays include LCD monitors, LCD screens, and plasma monitors. All flat-panel displays and some CRT monitors have a flat screen. The term, flat screen, means the screen is not curved.

3. What factors affect the quality of an LCD monitor or LCD screen?

An LCD monitor is a desktop monitor that uses liquid crystal display to produce images. These monitors produce sharp, flicker-free images. The quality of an LCD monitor or LCD screen depends primarily on its resolution, response time, brightness, dot pitch, and contrast ratio.

·         -Resolution is the number of horizontal and vertical pixels in a display device. For example, a monitor that has 1440 x 900 resolution displays up to 1440 pixels per horizontal row and 900 pixels per vertical row, for a total of 1,296,000 pixels to create a screen image. Recall that a pixel (short for picture element) is a single point in an electronic image. A higher resolution uses a great number of pixels and thus provides a smoother, sharper, and clearer image. As you increase the resolution, however, some items on the screen appear smaller. With LCD monitors and screens, resolution generally is proportional to the size of the device. For example, a widescreen 19-inch LCD monitor typically has a resolution of 1440 x 900, while a widescreen 22-inch LCD monitor has a resolution of 1680 x 1050. LCDs are geared for a specific resolution, called the native resolution. Although you can change the resolution to any setting, for optimal results, use the monitor’s native resolution setting.

·         -Response time of an LCD monitor or screen is the time in milliseconds (ms) that it takes to turn a pixel on or off. LCD monitors’ and screens’ response times range from 3 to 16 ms. The lower the number, the faster the response time.

·         -Brightness of an LCD monitor or LCD screen is measured in nits. A nit is a unit of visible light intensity equal to one candela (formerly called candlepower) per square meter. The candela is the standard unit of luminous intensity. LCD monitors and screens today range from 250 to 550 nits. The higher the nits, the brighter the images.

·         -Dot pitch, sometimes called pixel pitch, is the distance in millimeters between pixels on a display device. Text created with a smaller dot pitch is easier to read. Advertisements normally specify a monitor’s dot pitch or pixel pitch. Average dot pitch on LCD monitors and screens should .30 mm or lower. The lower the number, the sharper the image.

·         Contrast ratio describes the difference in light intensity between the brightest white and darkest black that can be displayed on an LCD monitor. Contrast ratios today range from 500:1 to 2000:1. Higher contrast ratios represent color better.

4. What are various ways to print?

Until a few years ago, printing a document required connecting a computer to a printer with a cable. Although many users today continue to print using this method, a variety of printing options are available.

Today, wireless printing technology makes the task of printing from a notebook computer, smart phone, or digital camera much easier. Two wireless technologies for printing are Bluetooth and infrared. With Bluetooth printing, a computer or other device transmits output to a printer via radio waves. The computer or other device and the printer do not have to be aligned with each other; rather, they need to be within an approximate 30-foot range. With infrared printing, a printer communicates with a computer or other device using infrared light waves. To print from a smart phone, for example, a user lines up the IrDA port on the smart phone with the IrDA port on the printer.

Instead of downloading photos from a digital camera to a computer, users can print these digital photos using a variety of techniques. Some cameras connect directly to a printer via a cable. Others store photos on memory cards that can be removed and inserted in the printer. Some printers have a docking station, into which the user inserts the camera to print photos stored in the camera.

Finally, many home and business users print to a central printer on a network. Their computer may communicate with the network printer via cables or wirelessly.

5. How is a nonimpact printer different from an impact printer?

·         A printer is an output device that produces text and graphics on a physical medium such as paper. Printed information, called hard copy exists physically and is a more permanent form of output than that presented on a display device (soft copy).

·         A nonimpact printer forms characters and graphics on a piece of paper without actually striking the paper. Some spray ink, while others use heat or pressure to create images. Commonly used nonimpact printers are ink-jet printers, photo printers, laser printers, thermal printers, mobile printers, label and postage printers, plotters, and large-format printers.

6. What are ink-jet printers, photo printers, laser printers, multifunction peripherals, thermal printers, mobile printers, label and postage printers, and plotters and large-format printers?

·         Ink-jet printers: An ink-jet printer is a type of nonimpact printer that forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper. Ink-jet printers have become a popular type of color printer for use in the home. A reasonable quality ink-jet printer costs less than $100. Ink-jet printers produce text and graphics in both black-and-white and color on a variety of paper types. These printers normally use individual sheets of paper stored in one or two removable or stationary trays. Ink-jet printers accept papers in many sizes, ranging from 3 x 5 inches to 8 ½ x 14 inches. Available paper types include plain paper, ink-jet paper, photo paper, glossy paper, and banner paper. Most ink-jet printers can print photographic-quality images on any of these types of paper.

·         -Photo printers: A photo printer is a color printer that produces photo-lab-quality pictures. Some photo printers print just one or two sizes of photos, for example, 3 x 5 inches and 4 x 6 inches. Others print up to letter size, legal size, or even larger. Some even print panoramic photos. Generally, the more sizes the printer prints, the more expensive the printer. Many photo printers use ink-jet technology. With models that can print letter-sized documents, users connect the photo printer to their computer and use it for all their printing needs. For a few hundred dollars, this type of photo printer is ideal for the home or small business user. Other photo printer technologies are discussed later in the chapter. Most photo printers are PictBridge enabled, so that you can print photos directly from a digital camera by connecting a cable from the digital camera by connecting a cable from the digital camera to a USB port on the printer.

·         Laser printers: A laser printer is a high-speed, high-quality nonimpact printer. Laser printers are available in both black-and-white and color models. A laser printer for personal computers ordinarily uses individual 8 ½ x 11-inch sheets of paper stored in one or more removable trays that slide in the printer case. Some laser printers have built-in trays that accommodate different sizes of paper, while others require separate trays for letter-and legal-sized paper. Most laser printers have a manual feed slot where you can insert individual sheets and envelopes. Laser printers print text and graphics in high-quality resolutions, usually 1200 dpi for black-and-white printers and up to 2400 dpi for color printers. While laser printers usually cost more than ink-jet printers, many models are available at affordable prices for the home user. Laser printers usually print at faster speeds than ink-jet printers.

·         Multifunction peripherals: A multifunction peripheral (MFP), also called an all-in-one device, is a single device that looks like a printer or a copy machine but provides the functionality of a printer, scanner, copy machine, and perhaps a fax machine. A fax machine is a device that codes and encodes documents so that they can be transmitted over telephone lines. The documents can contain text, drawings or photos, or can be handwritten. The features of these devices vary. Another advantage of these devices is they are significantly less expensive than if you purchase each device separately. If the device breaks down, however, you lose all four functions, which is the primary disadvantage.

·         Thermal printers: A thermal printer generates images by pushing electrically heated pins agains heat-sensitive paper. Basic thermal printers are inexpensive, but the print quality is low and the images tend to fade over time. Self-service gas pumps often print gas receipts using a built-in lower-quality thermal printer. Many point-of-sale terminals in retail and grocery stores also print purchase receipts on thermal paper. Two special types of thermal printers have high print quality and can print at much faster rates than ink-jet and laser printers. A thermal wax-transfer printer generates rich, nonsmearing images by using heat to melt colored wax onto heat-sensitive paper. Thermal wax-transfer printers are more expensive than ink-jet printers, but less expensive than many color laser printers.

·         Mobile printers: a mobile printer is a small, lightweight, battery-powered printer that allows a mobile user to print from a notebook computer, smart phone, or other mobile device while traveling. Barely wider than the paper on which they print, mobile printers fit easily in a briefcase alongside a notebook computer. Mobile printers mainly use ink-jet, thermal, thermal wax-transfer, or dye-sublimation technology. Many of these printers connect to a USB port. Others have a built-in wireless port through which they communicate with the computer wirelessly.

·         Label printer: a label printer is a small printer that prints on an adhesive-type material that can be placed on a variety of items such as envelopes, packages, optical discs, photos, file folders, and toys. Most label printers also print bar codes. Label printers typically use thermal technology.

·         Postage printer: A postage printer is a special type of label printer that prints postage stamps. Some have built-in digital scales for weighing letters and packages. Postage printers allow users to buy and print digital postage, often called Internet postage, which means you purchase an amount of postage from an authorized postal service Web site. Each time a postage stamp prints, your postage stamp prints, your postage account is updated. Although you can print Internet postage on an ink-jet or photo printer, postage printers can be more economical because they use thermal technology instead of ink catridges.

·         Plotters and large-format printers: Plotters are sophisticated printers used to produce high-quality drawings such as blueprints, maps, and circuit diagrams. These printers are used in specialized fields such as engineering and drafting and usually are very costly. Current plotters use a row of charged wires to draw an electrostatic pattern on specially coated paper and then fuse toner to the pattern. The printed image consists of a series of very small dots, which provides high-quality output. Using ink-jet printer technology, but on a much larger scale, a large-format printer creates photo-realistic-quality color prints. Graphic artists use these high-cost, high-performance printers for signs, posters, and other professional quality displays. Plotters and large-format printers can accommodate paper with widths up to 98 inches because blueprints, maps, signs, posters and other such blueprints, maps, signs, posters and other such drawings and displays can be quite large. Some plotters and large-format printers use individual sheets of paper, while others take large rolls.

7. What are the uses and characteristics of speakers, headphones, and earbuds?

·         An audio output device is a component of a computer that produces music, speech, or other sounds, such as beeps. Three commonly used audio output devices are speakers, headphones, and earbuds. Most personal computers and mobile devices have a small internal speaker that usually emits only low-quality sound. Thus, many users attach surround sound speakers or speaker systems to their computers, including game consoles and mobile devices, to generate higher-quality sounds for playing games, interacting with multimedia presentations, listening to music, and viewing movies. Most surround sound computer speaker systems include one or two center speakers and two or more satellite speakers that are positioned so that sound emits from all directions.

·         When using speakers, anyone in listening distance can hear the output. In a computer laboratory or other crowded environment, speakers might not be practical. Instead, users can listen through wireless headphones or earbuds or plug the device in a port on the sound card, in a speaker, or on the front of the system unit. With headphones or earbuds, only the individual wearing the headphones or earbuds hears the sound from the computer. The difference is that headphones cover or are placed outside the ear, whereas earbuds or earphones rest inside the ear canal. Both headphones and earbuds usually include noise-cancelling technology to reduce the interference of sounds from the surrounding environment.

8. What are the purposes and features of data projectors, interactive whiteboards, and force-feedback game controllers and mobile devices?

·         A data projector is a device that takes the text and images displaying on a computer screen and projects them on a larger screen so that an audience can see the image clearly. For example, many classrooms use data projectors so that all students easily can see an instructor’s presentation on the screen. Some data projectors are large devices that attach to a ceiling or wall in an auditorium. Some operating systems allow projectors to be part of the network, which enables a presenter to operate remotely via a network connection. Others, designed for the mobile user, are small portable devices that can be transported easily. Two types of smaller, lower-cost units are LCD projectors and DLP projectors. An LCD projector, which uses liquid crystal display technology, attaches directly to a computer, and uses its own light source to display the information shown on the computer screen.

·         An interactive whiteboard is a touch-sensitive device, resembling a dry-erase board, that displays the image on a connected computer screen. A presenter controls the computer program by clicking a remote control, touching the whiteboard with special digital pen and eraser, or writing on a special tablet. Notes written on the interactive whiteboard can be saved directly on the computer. Interactive whiteboards are used frequently in classrooms as a teaching tool, during meetings as a collaboration tool, and to enhance delivery of presentations.

·         Force-Feedback Game Controllers and Tactile Output: Today’s joysticks, wheels, gamepads, and motion-sensing game controllers also include force feedback, which is a technology that sends resistance to the device in response to actions of the user. For example, as you use the simulation software to drive from a smooth road onto a gravel alley, the steering wheel trembles or vibrates, making the driving experience as realistic as possible. These devices also are used in practical training applications such as in the military and aviation. Some input devices, such as smart phone, include tactile output that provides the user with a physical response from the device. For examples, users may sense a bumping feeling on their hand while scrolling through a smart phone’s contact list.

9. What output options are available for physically challenged users?

For users with mobility, hearing, or vision disabilities, many different types of output devices are available.

·         Hearing-impaired users, for example can instruct programs to display words instead of sounds. With the latest Windows operating systems, users also can set options to make programs easier to use. The Magnifier, for example, enlarges text and other items in a window on the screen.

·         Visually impaired users can change Windows settings, such as increasing the size or changing the color of the text to make the words easier to read. Instead of using a monitor, blind users can work with voice output via Windows Narrator. That is, the computer reads the information that is displayed on the screen. Another alternative for visually impaired users, is a Braille printer, which prints out information on paper in Braille letters.