Presentation on theme: "Display Devices Display device: output device that presents output visually Monitor/Display screen: The display device used with desktop computers, notebook."— Presentation transcript:
1Display DevicesDisplay device: output device that presents output visuallyMonitor/Display screen: The display device used with desktop computers, notebook computers, handheld PCs, smart phones, consumer devices, and many other devices
3Display Device Characteristics Usually color, but can be monochromeCan be a CRT monitor or a flat-panel displayCRT monitor: projects images onto a display screen using technology similar to that of TVsFlat-panel display: forms images by manipulating electronically charged chemicals or gases sandwiched between thin panes of glass or a liquid crystal. Popular flat panels displays are Plasma screens and LCD screens.
6Display Device Characteristics, Cont’d Size (measured diagonally)Screen resolutionCan be changedHigher resolution = more data on the screen at one time
7Display Device Characteristics, Cont’d Video card (determines display characteristics and how monitor can connect to the PC)Monitors can be also be:Wired or wireless2D or 3D DisplaysDigital TV and/or HDTV ready or capable
8Flat-Panel Display Technologies Liquid crystal displays (LCDs): use charged liquid crystals to display imagesOrganic light emitting diode (OLED) displays: use emissive organic material to display brighter and sharper imagesPlasma displays: use layers of gas to display images; most often used on large displays
10Monitors - Comparing Monitors When comparing monitors, consider four features:SizeResolutionRefresh rateDot pitch
11Comparing Monitors - Size A monitor's size is the diagonal measurement of its face, in inches.For years, 15" monitors (13"viewing area) were standard.Today, 17" monitors (15" viewing area) are common.Larger monitors are available, but can be expensive.
13Comparing Monitors - Resolution Resolution is the number of pixels on the screen, expressed as a matrix (such as 600x800).A 17" monitor offers resolutions from 640x480 up to 1280x1024.The Video Graphics Array (VGA) standard is 640x480. Super VGA (SVGA) monitors provide resolutions of 800x600, 1024x768 or higher.
14Resolution (image sharpness) is important. (Especially for graphics, page layout, and CAD)
15Comparing Monitors - Refresh Rate Refresh rate is the number of times each second that the electron guns scan the screen's pixels.Refresh rate is measured in Hertz (Hz), or cycles per second.Look for a refresh rate of 72 Hz or higher. A slower rate may cause eyestrain.
17Comparing Monitors - Dot Pitch Dot pitch is the distance between the phosphor dots that make up a single pixel.In color monitors, three dots (red, green, and blue) comprise each pixel.Look for a dot pitch no greater than .28 millimeter.
19Monitors - Video Controllers The video controller is an interface between the monitor and the CPU.The video controller determines many aspects of a monitor's performance, such as resolution or the number of colors displayed.The video controller contains its own on-board processor and memory, called video RAM (VRAM).
20VRAM Video Control Board with Monitor Cable Graphic intensive applications suchas games require plenty of VRAM.
22Data and Multimedia Projectors Data projector: display device that projects all computer output to a wall or projection screenMost data projectors today can project video, in addition to computer output.Can be wireless projectors
23Printers Printer: output device that produces output on paper Produce hard copyCan be used with both desktop and portable PCsPrinter characteristicsImpact vs. nonimpact printingMost printers are nonimpactImpact printers (like dot-matrix printers) are still used for printing multipart forms and shipping documents
24Printers Printer characteristics, cont’d Can print in color or black-and whiteCan be a personal or network printerQuality is called print resolution and measured in dots per inch (dpi)Print speed is measured in pages per minute (ppm)
25Laser PrintersLaser printer: output device that uses toner powder and technology similar to that of a photocopier to produce images on paperThe standard for business documentsPrint one entire page at a timeUsually black and white, though color printers are availableCommon print resolution for laser printers is between 600 and 2,400 dpi
27Ink-Jet PrintersInk-jet printer: output device that sprays droplets of ink to produce images on paperTypically print in colorOften the choice for home usePrint fairly slowly, one line at a timeQuality not quite as good as a laser printer
29Special Purpose Printers Photo printers (designed to print photographs)Barcode printers (print barcodes)Label printers (print labels, electronic postage, etc.)Portable printers (designed to be carried with you)Plotters and wide-format ink-jet printers (print on large paper or other large materials)
31Multifunction Devices Multifunction device: device that offers some combination of printing, copying, scanning, and faxing capabilitiesMost commonly, these types of devices are based on color ink-jet printer technology, although laser multifunction devices are availableAdvantage: takes up less space and is less expensive than purchasing multiple machinesDisadvantage: Lose all devices if it needs to be repaired
32Audio Output Audio output: output in the form of voice or music Speakers: connect to a PC and provide audio output for computer games, music, video, TV, videoconferencing, and other applications that have audio outputVoice output systems: produce spoken output