Computer Concepts Ch. 6-10

bar code reader

These devices are either handheld wand readers or platform scanners. They contain photoelectric cells that scan or read bar codes, or the vertical zebra-striped marks printed on product containers.

toggle keys

These keys turn a feature on or off

optical scanner

accepts documents consisting of text and/or images and converts them to machine-readable form. These devices do not recognize individual letters or images. Rather, they recognize light, dark, and colored areas that make up individual letters or images. four types: flatbed, document, portable, and 3D.

duplex printing

allows automatic printing on both sides of a sheet of paper. Although not currently a standard feature for all printers, it will likely become standard in the future as a way to reduce paper waste and to protect the environment.

touch screen

allows users to select actions or commands by touching the screen with a finger or penlike device

input

any data or instructions that are used by a computer. They can come directly from you or from other sources. You provide input whenever you use system or application programs.

output devices

any hardware used to provide or to create output. They translate information that has been processed by the system unit into a form that humans can understand. most common: monitors, printers, and audio-output devices.

repetitive strain injury (RSI)

any injury that is caused by fast, repetitive work that can generate neck, wrist, hand, and arm pain. RSI is by far the greatest cause of workplace illnesses, resulting in compensation claims totaling billions of dollars and lost productivity every year.

gaming mice

are similar to traditional mice with higher precision, faster responsiveness, programmable buttons, and better ergonomics.

media

are the physical material that holds the data and programs.

virtual reality

artificial, or simulated, reality created in 3D by computers. It strives to create a virtual or immersive experience by using specialized hardware that includes headgear and gloves.

wheel button

can be rotated to scroll through information that is displayed on the monitor.

multitouch screen

can be touched with more than one finger, which allows for interactions such as rotating graphical objects on the screen with your hand or zooming in and out by pinching and stretching your fingers.

digital cameras

capture images digitally and store the images on a memory card or in the camera's memory.

telephones

combine receiving and sending voice communication

headsets

combine the functionality of microphones and headphones. The microphone accepts audible input and headphones provide audio output.

joysticks

control game actions by users varying the pressure, speed, and direction of a control stick.

motion-sensing devices

control games by user movements. For example, Microsoft's Kinect accepts user movements and spoken commands to control games on the Xbox 360.

mouse

controls a pointer that is displayed on the monitor

scanning devices

convert scanned text and images into a form that the system unit can process. five types: optical scanners, card readers, bar code readers, RFID readers, and character and mark recognition devices.

audio input devices

convert sounds into a form that can be processed by the system unit. By far the most widely used device is the microphone.

3D Printers

create three-dimensional shapes by adding very thin layer after layer of material until the final shape is fully formed.

e- readers

dedicated mobile devices for storing and displaying e-books and other electronic media including electronic newspapers and magazines.

ultra-high-definition-television (UHDTV)

delivers a much clearer and more detailed wide-screen picture than regular HDTV. Because the output is digital, users can readily freeze video sequences to create high-quality still images. The video and still images can then be edited and stored for later use. This technology is very useful to graphic artists, designers, and publishers

gamepads

designed to be held by two hands and provide a wide array of inputs including motion, turning, stopping, and firing.

game controllers

devices that provide input to computer games

optical mouse

emits and senses light to detect mouse movement. Traditionally, the detected movements are communicated to the system unit through a cord. most widely used mouse.

storage devices

hardware that reads data and programs from storage media. Most also write to storage media.

input devices

hardware used to translate words, numbers, sounds, images, and gestures that people understand into a form that the system unit can process. These include pointing, scanning, image capturing, and audio-input devices.

VR headgear

has earphones and three-dimensional stereoscopic screens

VR gloves

have sensors that collect data about your hand movements. Coupled with software, this interactive sensory equipment lets you immerse yourself in a computer-generated world.

Combination i/o devices

headsets, MFD, telephones, drones, robots, and virtual reality headgear

grayscale

images are displayed using many shades of gray. Color is used more selectively for final reports containing graphics and for photographs

contrast ratios

indicate a monitor's ability to display images. It compares the light intensity of the brightest white to the darkest black. The higher the ratio, the better the monitor

aspect ratio

indicates the proportional relationship between a display's width and height. Typically, this relationship is expressed by two numbers separated by a colon

Card Readers

interpret encoded information on a card (Name, ID, signature, etc.) most common type is a magnetic card reader

active display area

measured by the diagonal length of a monitor's viewing area.

speed (printer)

measured in the number of pages printed per minute

capacity

measures how much a particular storage medium can hold.

access speeds

measures the amount of time required by the storage device to retrieve data and programs.

Important characteristics of secondary storage

media, capacity, storage devices, and access speed

organic light-emitting diode (OLED)

monitors replace the LED monitor's backlighting technology with a thin layer of organic compound that produces light

light-emitting diode (LED)

monitors use similar technology with a more advanced backlighting technology. They produce better-quality images, are slimmer, and are more environmentally friendly as they require less power and use fewer toxic chemicals to manufacture.

keyboards

most common way to input data. they convert numbers, letters, and special characters that people understand into electrical signals. These signals are sent to, and processed by, the system unit.

monitors

most frequently used output device. present visual images of text and graphics.

flat-panel monitors

most widely used type of monitor today. Compared to other types, they are thinner, are more portable, and require less power to operate.

flatbed

much like a copy machine. The image to be scanned is placed on a glass surface, and the scanner records the image.

drones

nexpensive, faster, and smarter, making them a valuable tool and fun high-tech toy. combination of video and aerial maneuverability

resolution

one of the most important features of clarity. expressed as a matrix of dots or pixels.

Carpal tunnel syndrome

one type of RSI found among heavy computer users, consists of damage to nerves and tendons in the hands. Some victims report the pain is so intense that they cannot open doors or shake hands and that they require corrective surgery. Ergonomically correct keyboards have been developed to help prevent injury from heavy computer use.

soft copy

output in the form of visual images of text and graphics

stylus

penlike device typically used with tablets and mobile devices. uses pressure to draw images on a screen. Often interacts with the computer through handwriting recognition software

combination keys

perform an action when held down in combination with another key.

hardy copy

printer output

cloud printers

printers connected to the Internet that provide printing services to others on the Internet

output

processed data or information, typically takes the form of text, graphics, photos, audio, and/or video.

E-ink

produces images that reflect light like ordinary paper, making the display easy to read. Two well-known e-book readers are Amazon's Kindle and Barnes & Noble's Nook Simple Touch.

digital projectors

project the images from a traditional monitor onto a screen or wall. This is ideal for presentations or meetings when several people need to see the screen at the same time. Further, projectors tend to be more portable and less expensive than a similarly sized monitor. Unfortunately, projected images can be difficult to see in bright rooms, so they are best used in dark rooms with curtains or no windows.

pointing devices

provide an intuitive interface with the system unit by accepting physical movements or gestures such as a finger pointing or moving across a screen and converting these movements into machine-readable input.

color capability

provided by most printers today. Users typically have the option to print either with just black ink or with color.

density

refers to how tightly magnetic charges fro hard disks can be packed next to one another on the disk.

clarity

refers to the quality and sharpness of the displayed images. It is a function of several monitor features, including resolution, dot pitch, contrast ratio, size, and aspect ratio.

optical mark recognition

senses the presence or absence of a mark, such as a pencil mark. often used to score standardized multiple-choice tests.

voice over IP (VoIP)

set of standards or technologies that support voice and other types of communication over the Internet.

document

similar to a flatbed scanner except that it can quickly scan multipage documents. It automatically feeds one page of a document at a time through a scanning surface.

resolution

similar to monitor resolution. It is a measure of the clarity of images produced.

plotters

special-purpose printers for producing a wide range of specialized output. Using output from graphics tablets and other graphical input devices, plotters create maps, images, and architectural and engineering drawings.

interactive whiteboards

specialized devices with a large display connected to a computer or projector. The computer's desktop is displayed on the digital whiteboard and controlled using a special pen, a finger, or some other device.

webcams

specialized digital video cameras that capture images and send them to a computer for broadcast over the Internet.

inkjet printers

spray ink at high speed onto the surface of paper. This process produces high-quality images in a variety of colors, making it ideal for printing photos.

dot (pixel) pitch

the distance between each pixel

ergonomics

the study of human factors related to things people use. It is concerned with fitting the task to the user rather than forcing the user to contort to do the task. For computer users and manufacturers this means designing input and output devices to increase ease of use and to avoid health risks.

traditional keyboards

these full-size keyboards are widely used on desktops and larger computers.

laptop keyboards

these keyboards are smaller than traditional keyboards and are widely used on laptop computers.

thumb keyboards

these keyboards are used on smartphones and other small mobile devices. Designed primarily for communicating via texting and connecting to the web, these keyboards are very small.

virtual keyboards

these keyboards are used primarily with mobile devices and tablets.

RFID (radio frequency identification) tags

tiny chips that can be embedded in most everything. They can be found in consumer products, driver's licenses, passports, and any number of other items. These chips contain electronically stored information that can be read using an RFID reader located several yards away. They are widely used to track and locate lost pets; to monitor production and update inventory; and to record prices, product descriptions, and locations of retail items.

e-books

traditional printed books in electronic format. These books are available from numerous sources including many public and private libraries, bookstore websites, and the cloud.

audio-output devices

translate audio information from the computer into sounds that people can understand. The most widely used audio-output devices are speakers and headphones. These devices connect to a sound card within the system unit. This connection can be by cable to an audio jack on the system unit, or the connection can be wireless

printers

translate information that has been processed by the system unit and present the information on paper

handwriting recognition software

translates handwritten notes into a form that the system unit can process.

portable

typically a handheld device that slides across the image, making direct contact.

mutifunctional devices (MFD)

typically combine the capabilities of a scanner, printer, fax, and copy machine.

voice recognition systems

use a microphone, a sound card, and special software. These systems allow users to operate computers and other devices as well as to create documents using voice commands.

robots

use cameras, microphones, and other sensors as inputs. Based on these inputs, robotic outputs can be as complex as exploring damaged nuclear reactors to as simple as taking a photo.

thermal printers

use heat elements to produce images on heat-sensitive paper. These printers are widely used with ATMs and gasoline pumps to print receipts.

3D

use lasers, cameras, or robotic arms to record the shape of an object.

magnetic-ink character recognition

used by banks to automatically read those unusual numbers on the bottom of checks and deposit slips. A special-purpose machine known as a reader/sorter reads these numbers and provides input that allows banks to efficiently maintain customer account balances.

touch pad

used to control the mouse pointer and to make selections. they operates by moving or tapping your finger on the surface of a pad. These devices are widely used instead of a mouse with laptops and some types of mobile devices.

laser printers

uses a technology similar to that used in a photocopying machine. they use a laser light beam to produce images with excellent letter and graphics quality.

cordless/wireless mouse

uses radio waves or infrared light waves to communicate with the system unit. These devices eliminate the mouse cord and free up desk space.

curved monitors

uses similar technology as flat-panel monitors except it has a concave screen that provides better viewing angles near the edges of the screen.

optical-character recognition

uses special preprinted characters that can be read by a light source and changed into machine-readable code. most common is the handheld wand reader. These are used in department stores to read retail price tags by reflecting light on the printed characters.

mouse pointer

usually appears in the shape of an arrow. It frequently changes shape, however, depending on the application

pixels

what an image is made up of

dots per inch

what printer resolution is measured in

universal product codes (UPC's)

widely used by retail stores to automate the processes to check out customers, to change product prices, and to maintain inventory records.

MaxiCode

widely used by the United Parcel Service (UPS) and others to automate the process of routing packages, tracking in-transit packages, and locating lost packages.

liquid crystal display (LCD)

widely used for older monitors and is typically less expensive.

memory (printer)

within a printer is used to store printing instructions and documents waiting to be printed.