Chapter 4-IT Flashcards
Input and Output
Keyboards
An input device used to enter characters at the location marked by the insertion point or cursor(where the next character will appear)
Mice
A mouse is a common pointing device that the user slides to move a pointer around the screen and clicks to make selections
Stylus
A pen-like device used to draw or write electronically on the screen
Digital forms
With handwriting recognition, written text can be converted to editable typed text
Perceptual computing
Users control devices with 3D gestures, voice commands and facial expressions
non-contact system
Touch screens
Display devices that are touched with the finger to select commands or otherwise provide input to the computer
Surface Hub-large multi-touch wall-mounted display
Table PC-large computer either built into a table or designed to be used on a table
Augmented reality
Overlays computer generated images on top of real-time images
Scanners
Is an input device that captures an image of an object in digital form
Flatbed(scan flat objects one page at a time)
Portable(scan objects while on the go)
3D scanners(scan objects in 3D)
Scanning quality and resolution
Quality of scanned images indicated by optical resolution
measured in number of dots per inch
Can often be specified when image is scanned
Can be changed when scanned image is edited
Barcodes
Are machine-readable optical codes that represent data as a set of bars
Types of barcodes
Read by traditional barcode reader
Universal product code(UPC)
ISBN
Code 39
Read by mobile apps
QR codes(2D;hold much more data)
Digital watermarks(icons)
Radio Frequency ID(RFID)
Shipping, warehousing
Is a technology that stores, reads and transmits data located in RFID tags
RFID tags contain tiny chips and radio antennas
Can be attached to objects
Read by RFID readers
Tags need to be within range of the reader, rather than in line of sight
Tracking inventory and assets
Electronic toll collection
IDs
Near field communications
A short-range wireless communication standard based on RFID
Used to transfer information between smartphones or between a smartphone and an NFC-enabled reader
Used for contact-less mobile payments
Optical mark readers
Input data from optical forms to score or tally exams, questionnaires and ballots
Optical character recognition
Recognizes text characters and converts them to electronic form as text, not images
Identifies each character and convert it to editable text
Used to process turnaround documents like monthly bills
Magnetic ink character recognition(MICR)
Is used primarily for banking to facilitate check processing
MICR readers(check scanners) read the MICR characters printed at the bottom of checks
Used by banks
Used by businesses to remotely deposit checks
Audio vs voice input
Audio-the process of entering audio data in to the computer
Voice input-Inputting spoken words and converting them to digital form via microphone or headset
Speech recognition
Systems enable the device being used to recognize voice input as spoken words
CRT vs flat-panel displays
Cathode ray tube(CRT) displays large, bulky and heavy
Flat-panel displays :take up less desk space ,use less power
Screen resolution
The no. pixels used on a display determines its resolution
Affects the amount of information that can be displayed on the screen at one time
Video adapters, interfaces and ports
Video cards determine the graphic capabilities of a computer
VGA, DVI,HDMI
Flat panel display technologies
Liquid crystal displays(LCDs) uses charged liquid crystals between sheets of glass/plastic
requires backlighting
Organic light emitting diode(OLED) displays use layers of organic material
emit visible light so do not require backlighting
more energy efficient
Other types of OLEDs
Flexible OLED-displays built on flexible surfaces such as plastic or metallic foil
Transparent OLED-Displays are transparent, emit light toward top and bottom of display surface
Phosphorescent OLED-Process that results in much more conversion of electrical energy into light instead of heat
Wearable holographic displays
Project images on top of what the person wearing the display is already seeing
Microsoft HoloLens
Essentially a head-mounted computer
Does not need to connect to a smartphone/computer to function
Electronic paper(e-paper) displays
Displays use electronic ink (e-ink)
Used for e-readers and other devices
Easier to read in direct sunlight
Content can change wireless
Only uses power to change images, not maintain an image
Can be monochrome/color
Other types of flat panel displays
Interferometric modulator(IMOD) displays
Plasma displays
Interferometric modulator displays
Essentially a complex mirror that uses external light to display images
Designed initially for mobile phones and portable devices
Images are bright and clear even in sunlight
Plasma displays
Use layers of gas between two plates of glass being replaced by LCDs
Data projectors
Display output from a computer to a wall or projection screen
Pico projectors
Keyboard projectors
3D projectors
Printer characteristics
Print resolution(measured in dpi)
Print speed(measured in pages per minute or images per minute)
Impact printers
Dot-matrix
Print mechanism strikes on inked ribbon to transfer ink to paper
Used to produce multiport forms
Non-impact printers
Ink-jet/laser
Use liquid ink/toner
Produce higher quality images
Much quieter than impact printers
Multifunction devices(MFDs)
All-in-ones
copy, fax, scan, print
Laser printers
Use toner powder and technology similar to that of a photocopier to produce images on paper
Faster and have better quality output than ink-jet printers
Use toner cartridges; toner is transferred to the paper and fused with heat
Ink-jet printers
Spray droplets of ink to produces images on paper
Use ink cartridges
Print more slowly
Relatively inexpensive with good quality output
Special purpose printers
Barcode printers(print a variety of barcodes)
RFID printers(encode RFID tags)
Label printers(print labels and or postage)
Photo printers
Portable printers
Integrated and large format ink-jet printers
Built into smartphones
Large-called plotters, some print on fabric and print up to about 120 inches in width
3D printers
Form output in layers to build a 3D version of desired output
Can print using plastic, metal
Called addictive manufacturing
Print customized objects on-demand
Personal products
Medical products
Can contain moving parts
