Introduction to Computer Information Systems/Input and Output

From Wikibooks, open books for an open world
< Introduction to Computer Information Systems
Jump to: navigation, search

Keyboards, Pointing, and Touch Devices[edit]


Keyboards are one of the many different types of input devices, and one of the most common. Most if not all keyboards are set up in an alphanumeric key arrangement, also referred to as a qwerty keyboard.[1] There are a few different ways a keyboard can connect to a computer, either wired or wireless, via USB or Bluetooth respectively. For the most part all keyboards are similar to one another, some may have extra keys for games and others may have a numerical keypad built into the board itself.

Logitech Gaming-Keyboard G15

While not all computing devices have keyboards they do have supplements, such as a on screen touch keyboard. Many phones have a slide out keyboard for those who prefer an actual physical keyboard. Speaking of physical keyboards, many tablets allow you to purchase a keyboard dock. All of these additional keyboards that you could add to devices are most likely membrane keyboards. Membrane keyboards are the cheapest and most common types of keyboards. The other growing type of keyboards are mechanical keyboards. When you type on a membrane keyboard you complete a circuit which produces the data on screen, which generally makes little to no sound and gives no tactile feedback. For many gamers and avid typist, they would use a mechanical keyboard, which has the point of contact directly beneath the each key. This gives a better tactile feedback along with a faster typing speed, but generally cost much more than membrane keyboards.[2]

keyboard is most importent part of computer

Different Types of Keyboards[edit]

The purpose of all keyboards is to input data, however, there are as many different types of keyboards as there are variations of devices that need one. At first, there was only one design for a keyboard, but just as all other technology has progressed with time, so has the keyboard. The “original” keyboard, known as the standard keyboard, is the QWERTY keyboard, which is probably the most familiar to people. This keyboard has an average 105 keys, and while minor changes have been made to the design, its overall format has stayed the same.[3]

Microsoft Natural Ergonomic Keyboard 4000

Due to the stress put on the wrist and hand muscles from typing, the ergonomic keyboard was invented. This keyboard has the keys split so that the angle of the user’s wrist is in a more comfortable and less-straining position. By improving posture, the Ergonomic Keyboard is supposed to prevent Carpal Tunnel Syndrome. It comes either as one separate board with pre-angled keys, or as two separate boards so the user can angle them any way he/she prefers.[4]

The other types of keyboards that have come along have been produced to fit very specific uses. For example, a gaming keyboard, as the name suggests, is made specifically for gamers and has special designs such as built-in joysticks. Another example is the internet keyboard, which have “hot keys” related directly to browsing the internet. These hot keys include bookmarks list, e-mail inbox, Google search, and YouTube.[5]

Lastly, there are keyboards made simply to be more convenient for the consumer. These include the wireless keyboard, which connects to a computer via Bluetooth, the compact keyboard, made for laptops and other portable devices, and the virtual (or touch screen) keyboard which is found mostly on mobile devices and tablets.[6] The last one is the most recently developed and will most likely come to be the only type of keyboard in the future.

The History of Keyboards[edit]

The first keyboards were called QWERTY keyboards named after the six letters in sequential order on the top left hand side of the keyboard. Surprisingly, the keyboard was actually designed to make typing as slow and difficult as possible. This is due to the fact that the very first design of the first typing machine developed by a man named Christopher Latham Scholes back in 1873 was originally set up in alphabetical order. After some time, it was typical for keys to get jammed together due to fast typing. This prompted Scholes to redesign the machine with the letters most commonly used as far away from each other as possible to avoid jamming. By making the user slow down, his new design became a success. It wasn’t until the 1960’s that a couple by the name of Bob and Joan Crozier came up with the idea that there was a need to integrate computer technology into business. At that time, there were only large mainframe computers available. The couple came up with a device that had keyboard switches, which led to more understanding about the growing need for such a device. By the 1970’s, the first keyboards were born. They had to be put together one switch at a time which was a lengthy process. Later in this decade, the first ever personal computers were developed. The keyboard was not attached to these computers so they required an IBM electric typewriter to be attached. By the 1980’s, IBM launched its first personal computers with their famous model M keyboards attached. This model came with some problems as it was criticized for its Enter and Shift keys being too small. IBM came up with keyboard expanders to fit the keyboard and enlarge the keys. By the 1990’s, Membrane switches became available to replace individual keys. This was also the decade that the laptop computer became available, making Membrane Switches to increase in popularity. The last decade has seen advancement in the design of the keyboard with the release of ergonomic keyboards that lessen the chance for a user to be injured due to overuse. Today, the modern keyboard faces extinction as the use of touch screen devices and voice recognition are taking the center stage of computer input.[7]

Point and Clicks[edit]

Inside a Wheel Based Mouse

Pointing devices are inputs that connect to a desktop or laptop and are used to move an on-screen pointer, usually an arrow, to allow the user to select objects on the screen. The most common of these is the "mouse" which derives its name from its size, shape, and "tail", or thin wire, which connects it to the computer. It's usually connected via a USB port and it often rests next to the keyboard for easy access. Recently, laser "mice" have become popular due their added mobility as these connect via Bluetooth or other wireless connection and and no longer need their "tails" for support to the system. Older mice have a ball at their base and use this to move the pointer on screen as the user's hand moves the mouse across the desktop surface. Once the pointer is over the desired icon, link, or image, etc. the mouse is used to interact with it by clicking one of the two buttons on it's surface. A wheel may also be found on some and is commonly used to scroll up or down a page or zoom in and out of a window. Optical mice use a laser on the bottom which track movement with light instead of a ball. Three dimensional mice may also be used to interact with three dimensional programs. These programs tend to recognize more complex movements and the mouse may be lifted to simulate flying or angled to simulate a visual tilt within the program.


stylus pens

Instead of using a mouse for a computer many systems allow there to be used a pen or stylus. The pens input could be drawing, writing, or tapping on the screen. The stylus often is just a piece of plastic and is just used to touch the screen and that’s it. The stylus could detect the amount of pressure that is applied to the screen that would allow you to have a more exact input. The stylus have a smooth rounded tip so it would not harm the screen it is used with, and could contain buttons so it could be similar to a mouse in that way and complete those type of functions. The stylus is used to be the most convenient like a pen a paper. Areas like photography, graphic design, animation, industrial design, and healthcare are using the stylus to aid to their profession more. There are even certain gestures that a pen can read to complete a task. Such as flicking the pen up could delete something, or print, or copy. The pens are beneficial for people with long nails, or are wearing gloves; nothing more annoying than having to take off gloves in the winter to have to use a touch screen device.The Galaxy Note 3 has a pen stylus that it comes with. This phone allows the user to use the screen to its fullest since the screen is so large, the phone embraces being able to use two hands while doing something on the phone.[8]

Touch Screens[edit]

Interactive table, Ideen 2020 exposition, 2013.

Touch screens are electronic visual displays which allow a user to interact with programs by using simple touch-based movements. Through the use of a special stylus/pen and/ or one or multiple fingers, the user can interact with the content being displayed in multiple ways allowing actions such as scrolling, zooming, rotating, dragging, and dropping items to be handled with ease without the need for a pointer or mouse. Because the touch screen interface can be used with practically any PC software and is useful in a variety of applications, mobile phones, tablets, desktops, laptops, and surface computers have taken advantage of this technology. It can be found in museums, consumer kiosks, newsrooms, automated teller machines (ATMs), medical field, etc. There are many touch screen technologies that have different methods of sensing touch, such as resistive, surface acoustic wave (SAW), capacitive, infrared grid, infrared acrylic projection, optical imaging, dispersive signal, and acoustic pulse recognition. They can recognize multiple inputs allowing for more than one person to operate the device at the same time as well as verify and pinpoint multiple objects that are place on them or near. Systems that use a stylus can recognize the differences in pressure applied to the screen and may even contain buttons to aid in "right-clicking" on an object.[9] The stylus is one of the most popular accessories in the touch-screen age.[10]

Fingerprint Scanners[edit]

A popular security option, which is now becoming standard on laptops and certain external hard drives, is fingerprint scanners. Small "touch screens" are placed adjacent to keyboards (or in the case of hard drives, on top of the hard drive) to prompt users to use their finger print as a means of secure login. Until recently, such hardware was expensive and unreliable. This means of input has been adapted by certain companies to increase security measures and provide peace of mind to clients (often in the case of physical cloud security). This technology was science fiction until recently and it has caught on in government use all the way down to the individual.

Other Pointing Devices[edit]


Examples of other pointing devices can be seen in gaming. A popular pointing device in video games is the joystick. Joysticks are moved by hand to point to an on-screen object, such as a character, and then a button or buttons are pressed to execute an action, for example jumping. Gamepads are also examples of pointing devices, performing similar functions to the joystick but held fully in hand instead. Another example of a pointing gaming device is a proprietary controller, such as the Wii remote. These devices are motion sensitive and require the controller to point into a sensor, which will move accordingly with an on-screen pointer. A trackball is a pointing device consisting of a ball in a socket, similar to an upside-down mouse, that the user rolls with the thumb, fingers, or palm. Trackballs are commonly seen on CAD workstations for ease of use. Control buttons and wheels are pointing devices commonly found on handheld gaming devices or portable digital media players. For instance, on an ipod, the user can spin the wheel to scroll though songs, and then click on the desired track. Touch pads are generally rectangular pads that a user can slide a thumb or fingertips across. Tapping the touch pad executes the same action clicking a mouse would. Touch pads are typically found on laptops and notebook computers. [11]

Specialized Pointing Devices[edit]

An ETC Ion Lighting Console. The control wheels are visible above the LCD screen

Depending on the device and applications being used, pointing devices can become quite specialized. Theater lighting boards have several different ways to input information due to the vast amount of equipment they can control. These can vary from joysticks to the more common control wheels. These wheels tell the lighting fixture to cycle between colors, change effects, and move on at x/y axis graph displayed on a screen. Besides lighting boards, flight simulators can have numerous input devices, most of which are customized to do a certain task. A number of manufacturers build throttle quadrants and aircraft yokes for use in home simulators. These devices can be set up in minutes, and mimic the movements of the actual aircraft controls. Airlines and colleges take this a step further, using immersive simulator that enclose the operator and mimic the movements of an aircraft in flight. In these simulators, the entire enclosure is one large input device, with each button and knob controlling some function. In addition, and instructor has a workstation where they can input commands and load scenarios to test the person flying the simulator. The full motion simulators used by airlines to train flight crews are perhaps the most complicated computer input devices.

Scanners, Readers, Digital Cameras[edit]

Flatbed Scanner


A scanner is a device that copies a picture in digital form. After capturing the image, the data is transferred to the computer. People use scanners to store their hand held pictures in their computer, and one might scan a document for business, school, etc. The two main types of scanners are flatbed and portable scanners. A flatbed scanner is the most common type of scanner, and it is designed to scan flat objects. A portable scanner is designed for travel purposes.[12]

Drum scanner

A sheet fed scanner is much like the flatbed scanner, only this may now be immobile and be used in stores to scan items on shelves. Optical scanners capture the image of a usually flat object and transfer it to a computer, much like flatbed scanners. In order to produce a better quality image, as most people strive for in their printing, you need a higher resolution scanner. The resolution of a scanner is measured in dots per 12-inches, which makes sense because the more dots you have, the more color that shows up, producing higher quality scans. Along with the resolution of a scanner comes the quality, which can be edited and improved once the image is scanned. If the user wants an extremely detailed scan, the drum scanner is a great tool to make this possible. It uses a photomultiplier tube to scan on a glass cylinder and send light rays in three beams, making light and color change and producing greatly detailed images.[13] There are even apps on our phone that we can personally scan documents to have on-the-go. The problem with this, however, is privacy issues and the crisis of having your phone or any other device stolen which has scanned any personal information. While scanners are a tremendous help especially in businesses, it is important users be aware of the risks and use with caution.

Although digital cameras are considered standard today, many individuals still have negatives from their days of using a film camera. This traditional film can easily be digitized using a specialized film scanner. Increasing the resolution will allow for higher quality reproductions of the images. [14]


Readers are designed to read the coding of different products. Readers are also called a "price scanner." It is usually a hand held device that captures the barcode on a certain tag, sticker, or twitter/facebook code. UPC (Universal Product Code) and ISBN (International Standard Book Number) are the two most famous barcodes. Barcodes are essential for efficiency in different businesses.[15]

Barcodes use lines to represent the numbers 0-9. They can be quite long, signifying a long string of numbers. These unique number combinations represent a variety information. Barcode readers interpret the bars in the code using reflected light or imaging technology. Once the bars are interpreted, the information that is tied to the number can be retrieved. The scanners can be stationary, like those found in stores, or portable, like those used by delivery services to scan packages.

Example of QR code

QR Codes and RFID tags[edit]

QR codes, otherwise known as quick response codes, are pattern display bar codes read by an imaging device, that enable a user to automatically scan and open to an encoded hyperlink by using their “smart device”. QR reader applications on devices enable the user to access the hyperlink. The hyperlink opens up to a URL on the user’s device, displaying an image, or website. QR codes are often used by companies to allow the most efficient, least expensive way of advertisement for their product, company, event, website, etc. These codes enable a potential customer or user to access their information with convenience. QR codes are also used in other aspects to identify time tracking, item identification product tracking, as well as document management.[16]

QR Codes are an expansion on traditional barcodes. Traditional barcodes are one dimensional, while QR codes are two-dimensional. Storing data both horizontally and vertically allows for a significant increase in combinations of information.

Example of a QR Code

"QR Code" is a type of matrix bar code originally created in 1994 by the Toyota Automobile Company. They were used during the manufacturing process in place of traditional bar code labels, which offer significantly less room to store data and were frequently damaged. Since the rise of smartphones (and downloadable QR scanning applications), they have experienced unprecedented growth in popularity and success from advertising/marketing, and have in a sense revolutionized these industries. QRCs save businesses money by offering an affordable and personalized way to promote their goods or services. Perhaps most importantly, however, they have given customers everywhere an entirely new way in which to access information, both quickly and conveniently. [17]

RFID codes, otherwise known as the Universal Product Code, in which the barcode is replaced by radio frequency identification tags, which allows communication between network systems that can track certain data or information. RFID codes are commonly used in our economy today in multiple different ways. In similarity to QR codes, RFID codes also allow a user efficiency time-wise as well as convenience-wise. Ways that RFID codes are used in our society consist of the following: inventory tracking, ticketing applications, mobile payments, as well as border security.[18]

Digital camera
Disassembled digital camera

Digital Cameras[edit]

Almost every American owns a digital camera to save their memories! Digital cameras are used to take a picture, and these pictures are usually stored in a memory card. When purchasing a camera, it is important to know how many mega pixels the camera contains.For example, the higher the mega pixels, better the quality the picture will turn out. However, usually, the higher the mega pixels, the more expensive the camera will cost. People enjoy cameras because the pictures are almost immediately accessible.[19]

Professional video camera

Today, digital cameras are often found integrated into various mobile devices.[20] When it comes to smartphones, the camera is often one of the most marketed features of the device. For instance, when shopping for a smartphone online, a website will often have an image that compares a picture taken by various competitor’s phones. The reason these cameras on smartphones are marketed to this extent is because they offer so many advantages to an average everyday consumer. A camera with the capability of snapping nice pictures allows someone to easily share daily activities to social media, scan barcodes at the grocery store, provide post-accident evidence for insurance, and so much more.[21]

While a digital camera can snap still images, a digital video camera can record videos. Although portable digital camcorders are slowly becoming unpopular in the market, other types of these cameras are used every day.[22] For example, these cameras are often used by buildings for surveillance, television networks for broadcasting, and companies for video conferences.[23] However, each type of camera used in these situations are different. Cameras used for security purposes are usually able to operate remotely, and are often found to be smaller than other cameras so that they are more inconspicuous. Television networks use expensive professional cameras which have many different function and are very high performance. Cameras used for video conferencing are often webcam cameras. These cameras are small, usually portable, and can be integrated with a laptop.[24] Overall, the digital video camera is a useful tool in today’s society.

One of the main appeals of digital cameras is the instant gratification of seeing the image immediately upon taking it. The instant gratification comes at a small price, however, because there is a slight delay between the pressing of the button and the actual taking of the photograph.

Biometric Readers[edit]

A U.S. soldier using a biometric eye scanner.

Biometrics are objective, measurable, biological traits that can be used to identify somebody.[25] Biometric identification is becoming more and more common, and individuals can be recognized by a computer based on everything from their eyes to their fingerprints, from their voice to their face, from their unique body odor to the shape of their ear. Some uses of biometrics include fingerprint scanners to protect sensitive information stored in databases at places like nuclear power plants, biometric identification at borders and on passports, identification at nightclubs to ensure people who have been banned can't enter, and even at public schools to have stronger records of attendance and library book borrowing.[26] While biometric authentication is incredibly useful, there can also, obviously, be strong privacy concerns if their use is becoming too common. However, an organization called the Biometrics Institute is seeking to not only advance the use of biometrics but also ensure that all privacy concerns are addressed as this kind of technology becomes more and more common, with a set list of privacy guidelines that should be met whenever and wherever biometric identification is being employed.

Audio Input and Output[edit]

Audio Input[edit]

Microphone used to input audio into a computer

Audio input is when audio data is put into a computer. Usually the audio that people put into computers is voice or music. Voice input is when words are spoken into a microphone on the computer and they are translated into the digital form via the microphone. Many people will use a sound recorder software to store the voice in a file. One thing that is becoming better known is speech recognition systems. An example of speech recognition being used is when you call a company and an automated voice recording answers and you speak to them and answer their questions and the computer is able to recognize what you are saying and take you where you need to go.[27] Many phones have speech recognition software that allows the user to speak their text message or anything else into their phone and the phone can type the text for them. However these programs are not perfect and they usually require the speaker to talk slowly and clearly. One new technology that is being developed has to do with computers picking up noises the hard drive is making and detecting if there are any problems. One way to input music into a computer is to input it from a CD. They also have keyboards that can be plugged into the computer and the sound can be inputted into the computer. With that technology they can also show the sheet music that was played.[28]

Speech Recognition[edit]

There are many different ways in which speech recognition systems work. One type of system is a speaker-independent speech recognition software which works no matter the user. Another type of system is a speaker-dependent system in which uses training to analyze a specific users voice. The system is then able to adjust to nuances in a persons voice and fine-tune the speech recognition. Another system is voice-recognition systems which are very similar to speaker-dependent systems in that they are dependent upon the speaker, but instead, they mostly focus on who is speaking rather than what they are saying. These types of systems are primarily used in personal security systems. Speech-recognition software is used to ease the users use of the computer and allow users the freedom of not having to use a keyboard or mouse to navigate through a computer system. Speech-recognition software can be used to perform many tasks including opening applications, making calls, calculating the amount of teaspoons in a cup, and even finding the nearest Chipotle. Today, the use of speech recognition systems are greatly advancing due to their incorporation in mobile devices such as Apple’s Siri and Windows Cortana. Also, speech recognition software has been included within the makings of cars due to regulations that require drivers to use hands-free devices to avoid distraction from the road. [29]

Parc Asterix 22

Speech detection and speech analysis are being used in robotics and automatic translation, access control systems and education, but not only a human speech is a subject of recognition. The created sound recognition software has a great scientific and practical value. A broken window, dolphin’s talks, faulty machinery unit, even flowing blood could be recognize due the sounds they make. Growing sound libraries and improving electronic equipment allows actively apply sound recognition technologies in areas such as industrial automation, home improvement, animal bioacoustics, medical bioacoustics and others. People use speech recognition to let computers understand them and use computers for sound recognition to better understand the world. [30]

Audio Output[edit]

Audio Output-Speakers

Audio Output is exactly how it sounds. These are the sounds heard while working on a computer, that incorporates voice, music, and other audio sounds. The most common type of audio output device are speakers. These are used to hear video games, music from iTunes [31] or YouTube,[32] TV shows on Netflix,[33] Web conferencing, and other types of programs. Most computers have the capability to add additional speakers for better sound quality. The speakers are usually included when the computer is bought. Other speakers vary in a broad span of prices. A subwoofer can be added to amplify the computer’s audio output. Subwoofer’s have low-pitched audio frequencies known as bass and are intended to strengthen the low frequency range of loudspeakers covering higher frequency bands.[34] They can be installed in automobiles and computers. For portable laptops and mobile devices, the speakers are built into the device. Some desktop computers have speakers permanently installed to the monitor. A unique example of audio output is a treadmill. Some treadmills have the ability to play music from an iPod or MP3 dock, which makes working out more enjoyable. With our rapidly growing and expanding market, recently many car companies have included headphone jacks, dock connections, or USB ports to connect an iPod or mobile device. These connections make it easier for the driver to listen to their own music from their iPod, instead of the radio or CD’s. Headphones can be used as audio outputs as well, instead of using speakers. Using headphones helps users not to disturb others around them (in a library or school).

Display Devices[edit]

Display Device Characteristics[edit]

Old Philips Television Set
Cathode Ray Tube

There are many different characteristics of display devices. These include display colors, monitor styles, resolutions, video compatibilities, and the extra abilities these devices may have. Most devices today have color displays but there are a few which still follow a monochromatic color scheme. The Nook eReader is one of these devices.[35] There is also a difference in the type of monitor in the way it is illuminated. The older style devices such as the large, clunky, heavy tv's and computer screens are lot with cathode-ray tubes (CRT) and because the tubes take up so much room, the devices needed to be much larger. Today most of our devices are flat-panel displays. These displays use a chemical or gas reaction between two thin clear pieces of material to create their display; this is why they are able to be much thinner and lighter than CRT devices.[36]

Buyer beware, when buying a new device keep in mind that the monitors are measured diagonally. So that new 7" tablet you are looking at on is 7" diagonally from corner to corner. If you expect the 7" to be the width, you will be sorely disappointed by the smaller device you receive.[37] Keep in mind also that resolution is important. The more information that can be shown in less space, the clearer the image and higher the resolution will be. Video is input through a video card which holds the GPU inside of it. The video card is used to translate the video information into an image that will appear on the monitor of your device. It uses a fairly large amount of RAM to do so. There are many ways of connecting video devices to computers, and one of those actually allows the addition of extra monitors to an existing computer allowing for double the screen space. Other interesting features of display devices include the ability to hold a charge (temporarily) on their own and become known as wireless, display images in 2D or 3D format, become much more mobile and even wearable (such as a virtual reality simulator headset), as well as register commands based on touch and motion (e.g. iPhone, iPad, Android phone, and most other "smart" devices today).

Data Projectors[edit]

With a data projector, this heartwarming picture can get a whole classroom teary-eyed.

While your computer has many talents and uses, sometimes it might seem as if there's not enough of it to go around. Let's say that there's a hilarious cat video on Youtube that you'd like to share among thirty of your best friends but there's not enough room for them all to huddle close before your glowing monitor. Instead of splitting the viewing party up in groups, you can use a data projector. A data projector lets you display what's on your computer monitor onto a wall or projection screen.[38] The image is blown up so all your friends can now laugh in unison as the Youtube cat extends its paws in surprise. Even if you didn't know the name for it, chances are very high that you've encountered a data projector sometime in your life, especially if you attend public school. They can transfer data from computer to projection screen either with a cord or through a wireless connection. For those of you who like to share on the go, there are even portable projectors called pico projectors that can provide a lesser quality but more accessible presentation.[39]

Flat Display Devices[edit]

Flat display devices have become increasingly popular over the years because of their slim design and accessibility. Monitors today must be able to provide full color and gray scale, high efficiency and brightness, the ability to display full-motion video, wide viewing angle, and a wide range of operating conditions.[40] Consumers today want these devices to be thin and light weight, be insensitive to magnetic fields, and not produce any x-rays. All of these attributes are not possible with the cathode ray tubes that are generally found in older televisions or monitors. There are electroluminescent displays, plasma display panels, vacuum fluorescent displays, and field-emission displays all being sold today. The first are used in industries and medical fields because of how durable they are under many temperatures. Plasma displays are usually used in televisions. Vacuum fluorescent displays are used for low information displays like on appliances or small electronics. Liquid-Crystal Displays (LCDS)are the most commonly manufactured displays at this time.

Unlike the old TVs with a "fat" back, the newer LED TVs are much thinner and energy efficient.

Without even realizing it, we are constantly surrounded by items containing an LCD since they are much thinner and lighter than other displays. Laptop computers, digital clocks, microwave ovens, watches, and many other everyday items all have an LCD. A liquid crystal display works by blocking light as it uses charged liquid crystals that are located between two glass sheets to light up the appropriate pixels using a backlight provided by fluorescent lamps. Conveniently, LCD panels typically already contain those lamps at the rear of the display, hence the term backlight. However, to preserve more energy, today’s new technology has invented light emitting diode displays (LEDs), which are now replacing the fluorescent lamps that were previously used.

LEDs are another flat-panel technology seen in many objects around us like alarm clocks, Christmas lights, and car headlights, etc. An advantage of an LED over an LCD is that they are a lot thinner, have brighter images, color, and quality than an LCD, or even Plasma. Also, since an LED does not require backlighting from fluorescent bulbs, which have a relatively short lifespan, it tends to have a much longer lifespan. As fluorescent lamps burn out more quickly, LEDs are better to use for applications that require turning on and off frequently. Another benefit of LED monitors is the fact that they consume much less power compared to LCDs; LEDs actually consume almost half as much power than an LCD consumes! [41]

Color generation for an IMOD display

A new flat-panel display technology is the interferometric modulator display. This display uses a reflective membrane and a thin-film stack, which sit on a transparent substrate, to reflect external light onto the display. The device uses the interference of light wavelengths to create the different colors necessary for color images. This new display technology is meant to be used for portable devices and new mobile phones. The reason for this is because the display consumes a very little amount of power. By only using external light, the device would not need to continually backlight the display. In fact, the only time the display would need to consume power is when changing the image. This allows for the image to stay open without losing any power for the device, something we all have to deal with everyday on our mobile phones. Another plus for the IMOD display is that the images will stay clear even when in direct sunlight, because it is actually using that sunlight for the image. This is definitely an advantage for anyone who has noticed how hard it is to use a portable device or mobile phone outside when it is sunny. The IMOD display technology is a very energy efficient technology that needs to be utilized in mobile phones and portable devices to help consumers with their issue over battery consumption.[42]

Video Adapters, Interfaces, and Ports[edit]


The graphics processing unit (GPU) is the chip devoted to rendering images on a display device. Devices either have a video card or an integrated graphics component built directly into the motherboard or the CPU. The GPU is located in the video card or the graphics component of the computing device. This is what determines the quality of the image that can be shown on a monitor. Video cards will usually contain a fan to cool the card. Video cards will either have a memory chip or they are designed to use a portion of the computer’s regular RAM as video RAM instead. Video cards contain between 256 MB and 2 GB of video RAM. The three most common types of interfaces used to connect a monitor to a computer are VGA (Video Graphics Array), DVI (Digital Visual Interface), and HDMI (High-Definition Multimedia Interface). These are the ports that can be found on a computer to connect it another device, such as a TV screen or a projector. Today, HDMI is used widely amongst major electronic companies like Toshiba, Sony, and Panasonic. This allows for high quality connection and single-cable capability to be used to interconnect devices not matter who manufactured the computer.[43]

Virtual/Augmented Reality Devices[edit]

Boy wearing Oculus Rift experiencing Virtual Reality

One of the recent advancements is that of Virtual Reality and Augmented Reality devices. These devices display information by immersion rather than by just displaying it on a screen. First, the distinction between Virtual Reality and Augmented Reality is that the former completely immerses the user in a different “virtual” environment while the latter adds or displays information to the current and existing environment. So while virtual reality brings you into a theatre, augmented reality brings the movie to your wall. Both of these are implemented through various devices. There are head-mounted displays. These are displays that are usually worn by the user and are seen through in order to experience either virtual or augmented reality. Those that do virtual reality usually cover the eyes so that the user is completely blocked out of the real world and can be fully immersed in virtual reality. Those that make use of augmented reality are usually see through since the objects are displayed in the real world environment. Then there are hand-held displays which usually only do augmented reality. These usually make use of the devices camera and screen in order to show virtual objects in the real world.[44]


Printers today can be divided into two main categories: impact printers and nonimpact printers. Impact printers (known as dot matrix printers) are the traditional printers that actually strike the paper with ink. Their primary uses are for the production of business forms like packing slips and receipts. On the other side are nonimpact printers. These printers do not touch the paper like impact printers, and there are two common types: laser and inkjet. Laser printers use ink powder and inkjet printers use ink, which both create the images with dots (similar to pixels on a monitor). These dots make up the print resolution, which is known as the dpi (dots per inch). The higher the resolution the sharper the image. General ranges for a dot matrix printer are 60-90 dpi, an inkjet 300-720 dpi, and a laser printer 600-2400 dpi.[45] With that, color printers and black-and-white printers are two standards found in either the home or office setting. Typically for home-use color printers are more common than offices, which will use black-and-white printers due to costs (unless the company needs color for specific materials and products like reports or brochures).

Advantages of laser printers include higher resolutions of the image, faster printing speed, and no smearing. However laser printers are more expensive than inkjet printers, which many people use because they are lower in cost yet still produce high quality images and remain relatively fast in operation. Besides these two types, the advantages of impact printers are their low printing cost per page, their ability to print on multi-part forms and their reliability. However these printers are much louder as well as slower than inkjet and laser printers.[46]

Personal printers and network printers are distinguishable by their connection to either a single computer or a home/office network. Network printers allow multiple computers to print from the same printer, which is why they are a standard in the business setting. Typically personal printers have a rate of 20 to 35 ppm (pages per minute) whereas network printers can print from 30 to 65 ppm.

Printers can connect via USB, wired or wireless networks, or connections from other devices such as memory cards or cameras. It is not uncommon to see printers that have multiple capabilities like copying, scanning and faxing. These inkjet or laser printers are known as multifunction devices and they can come in color or black-and-white options.

Laser Printer

Laser printers[edit]

Why choose laser printer over any other printer? Well, Laser Printers are known to be good for their speed, precision and economy. Since it uses a laser, it can print one page at a time so it’s known to be significantly faster than the ink-jet printers. Although they are more expensive than ink-jet, they seem to be more cost-efficient considering ink is more expensive than toner powder, which is used for laser printers. Laser printers are more reliable with their prints because ink-jet printers tend to leave ink smears. Static electricity is the primary principle in making the printer work, which is an electrical charge built up on an insulated object. It uses objects with opposite static electricity forcing the fields to cling together.

Laser printers can work in either black-and-white or in color. To print on a page, a piece of paper must be first be inserted into the loading tray of the printer. A laser beam electrically charges the drum in the necessary locations that the microprocessor in the computer has decoded based on the image being printed. The ink used is a fine powdered ink known as toner, which is applied while the paper rolls over the drum. The paper finally goes through a fusing unit which permanently binds the toner to the paper. [47] [48]

Ink-jet Printers

Ink jet printers: Why choose Ink-jet printers? Well, ink-jet printers create pictures by spraying ink from the ink cartridges onto the page. Depending on the printer there’s different sized ink droplets, nozzles and electrical charges for more precise printing. They are typically slower than laser printers because of the back and forth motion of the ink tray. Ink-jet printers have grown in popularity and performance while dropping significantly in price. These dots are thinner than a strand of hair and when different colors combined together to create photo-quality images. [49]

3D Printer

Special-Purpose Printers: Though almost every household has some sort of either ink jet printer or laser printer, there are also numerous special purpose printers out there that are made to perform a specific task. Many companies invest in these products to improve time and cost efficiency. Some examples of these printers are photo printers, bar code, label and postage printers, portable and integrated printers, and 3D printers. -Photo printers, as the name quite obviously gives it away, are used for the purpose of printing merely pictures. Often times, people invest in these printers because they produce a better quality picture than just a typical everyday printer would. They also have certain capabilities and apps that one would not just find on any printer. -Businesses are also often found using bar code, label, and postage printers for their products. Every sellable item needs a product label, and having a printer that is designed just for that saves both time and money. They are also useful for the electronic postage capabilities, saving companies time on the mass amount of envelops that they send out on a daily basis. -If you are an on the go businessman or woman, a portable or integrated printer is the way to go. With so much travel and back and forth, it is easy to pull out these commutable printers and print the documents or images you need on the fly. -Finally, possibly the newest and most up and coming printer is the 3D printer. This useful tool can be utilized for printing models and samples. It prints using plastic, and literally produces a finalized 3D prototype of what you want. With technology rapidly improving, more and more products are being designed for the purpose of cost and time efficiency. Depending on what you do on an every day basis, it may be a very wise choice to invest in one of these printers to save you valuable time and money in the long run. [50] -3D Printers

A 3D printed Beethoven.

3D printers use virtual designs created in advanced programs such as CAD (Computer Aided Design) or scanned using a 3D scanner to print out physical models and parts. In order to do this, the software must “slice” the model into thousands of layers that the printer lays down one at at time. There are various kinds of manufacturing methods, such as FDM where material is melted into layers or SLS printing where powdered material is sintered into layers.[51] 3D printing has many applications, especially in design. Even manufacturers now use the printers to create rapid prototypes for research. This saves companies both money and time since changes only need to be made the design file on the computer.[52]

There are different 3d printing methods that were developed to build 3D structures and objects. Some of them are very popular nowadays, others have been dominated by competitors. Most of popular types of 3d printers are:

- Fused deposition modeling (FDM) - 3D printing machines that use FDM Technology build objects layer by layer from the very bottom up by heating and extruding thermoplastic filament.

- Stereolithography (SLA) - SLA 3D printers work with excess of liquid plastic that after some time hardens and forms into solid object.

- Selective Laser Sintering (SLS) - Selective Laser Sintering (SLS) is a technique that uses laser as power source to form solid 3D objects. The main difference between SLS and SLA is that it uses powdered material in the vat instead of liquid resin as stereolithography does.

- Selective laser melting (SLM) - Selective laser melting (SLM) is a technique that also uses 3D CAD data as a source and forms 3D object by means of a high-power laser beam that fuses and melts metallic powders together.

- Electronic Beam Melting (EBM) - The same as SLM, this 3d printing method is a powder bed fusion technique. While SLM uses high-power laser beam as its power source, EBM uses an electron beam instead, which is the main difference between these two methods. The rest of the processes is pretty similar.

- Laminated Object Manufacturing (LOM) - During the LOM process, layers of adhesive-coated paper, plastic or metal laminates are fused together using heat and pressure and then cut to shape with a computer controlled laser or knife. [53]



barcode A machine-readable code that represents data as a set of bars.

computer speakers Output devices connected to computers that provide audio output.

CRT monitor A type of display device that projects images onto a display screen using a technology similar to the one used with conventional TVs.

data projector A display device that projects all computer output to a wall or projection screen.

graphics tablet A flat, rectangular input device that is used in conjunction with a stylus to transfer drawings, sketches, and anything written on the device to a computer.

handwriting recognition The ability of a device to identify handwritten characters.

headphones A personal audio output device used by an individual so only he or she can hear the sound

ink-jet printer An output device that sprays droplets of ink to produce images on paper.

keyboard An input device containing numerous keys that can be used to input letters, numbers, and other symbols.

laser printer An output device that uses toner powder and technology similar to that of a photocopier to produce images on paper.

liquid crystal display (LCD) A type of flat-panel display that uses charged liquid crystals to display images.

monitor A display device for a desktop computer.

mouse A common pointing device that the user slides along a flat surface to move a pointer around the screen and clicks its buttons to make selections.

multifunction device (MFD) A device that offers multiple functions (such as printing, scanning, and faxing) in a single unit.

optical character recognition (OCR) The ability of a computer to recognize scanned text characters and convert them to electronic form as text, not images.

organic light emitting diode (OLED) display A type of flat-panel display that uses emissive organic material to display brighter and sharper images. See organic light emitting diode (OLED) display

photo printer An output device designed for printing digital photographs.

pixel The smallest colorable area in an electronic image, such as a scanned image, a digital photograph, or an image displayed on a display screen.

pointing device An input device that moves an on-screen pointer, such as an arrow, to allow the user to select objects on the screen.

printer An output device that produces output on paper.

radio frequency identification (RFID) A technology used to store and transmit data located in RFID tags.

scanner An input device that reads printed text and graphics and transfers them to a computer in digital form.

speech recognition system A system, consisting of appropriate hardware and software, used to recognize voice input, such as dictation or audio computer commands.

stylus An input device that is used to write electronically on the display screen.

touch pad A small rectangular-shaped input device, often found on notebook and netbook computers, that is touched with the finger or thumb to control an on-screen pointer and make selections.

touch screen A display device that is touched with the finger to issue commands or otherwise provide input to the connected device.

Review Questions[edit]

The vocabulary may or may not be listed above. What am i?

1. The smallest area of an image in which makes up a whole image.

2. Two of the most familiar_____are UPC and ISBN.

3. A device that is designed to convert physical form to data.

4. With a typical ____________ the sounds are broken into digit representation of Phonemes.

5. An output device that uses toner powder and technology similar to that of a photocopier to produce images on paper.

6. The device that shares the information on a screen.

7. The ability of a device to identify handwritten characters.

8. A personal audio output device heard by an individual.

9. A display device that projects all computer output to a wall or projection screen.

10. An input device that moves an on-screen pointer, such as an arrow, to allow the user to select objects on the screen.


1. Pixel 2. Barcodes 3. Scanner 4. Speech Recognition System 5. Laser Printer 6. Moniter 7. Handwriting Recognition 8. Headphones 9. Data Projector 10. Pointing Device


  20. Understanding Computers: Today and Tomorrow Comprehensive 14th ed. by Morley & Parker
  21. Understanding Computers: Today and Tomorrow Comprehensive 14th ed. by Morley & Parker
  23. Understanding Computers: Today and Tomorrow Comprehensive 14th ed. by Morley & Parker