高等教育出版社影印版計(jì)算機(jī)專業(yè)英語(yǔ)習(xí)題5ch-7-im

1、Ch 5 Input and OutputLecture OutlineCompetencies pg 176Define input.Describe keyboard entry, pointing devices, and scanning devices.Discuss image capturing devices, digitizing devices, and audio input devices.Define output.Describe monitors, printers, and audio output devices.Discuss combination inp

2、ut and output devices.Introduction pg 177Computer Input and output devices are essentially translators.Input devices translate numbers, letters and actions that people understand into a form that the computer can process.Output devices translate the machine language the computer can process back int

3、o letters, numbers, sounds, and images that people can understand.Competent end users need to know about the most common input devices such as keyboards, mice, scanners, digital cameras, digitizing tablets, voice recognition devices, and MIDI.They also need to know about the most common output devic

4、es such as monitors, printers, and audio output.They also need to know about combination input/output devices such as fax machines, Internet telephones, and terminals.What is Input pg 178Input is any data or instructions that are used by a computer.They can come directly from you or from other sourc

5、es.Input devices are hardware used to translate words, sounds, images, and actions that people understand into a form that the system unit can process.Keyboard Entry pg 178Keyboards convert numbers, letters, and special characters into electronic signals.Most keyboards have their alphabetic characte

6、rs arranged in the standard QWERTY format (note the first six characters on the top row of a keyboard).KeyboardsTraditional keyboards: full-sized, rigid, rectangular keyboards that include function, navigational, and numeric keys.Flexible keyboards: fold or roll up for easy packing and storage for m

7、obile users.Ergonomic keyboards: similar to traditional, but designed to specifically alleviate wrist strain associated with repetitive movements of typing.Wireless keyboards: more expensive than traditional keyboards, but give the flexibility of un-tethering the cord.PDA keyboards: miniature keyboa

8、rds for PDAs for sending email, etc.FeaturesNumeric keypads: easier entry of numbers and arithmetic symbolsToggle keys: on off keys for such things as Caps Lock and Scroll LockCombination keys: perform an action when combined with other keys, e.g. key or keyPointing Devices pg 180MouseA mouse contro

9、ls the pointer displayed on the monitorThe mouse pointer usually appears in the shape of an arrowMechanical mouse: traditional mouse with a ball in the bottom and cord connecting it to the computerOptical mouse: has no moving parts it emits and senses light to detect mouse movement.Cordless or wirel

10、ess mouse: a battery operated device that typically uses radio waves or infrared light waves to communicate with the system.Other similar pointing devices include:Trackball (aka Roller Ball)Touch surfaces (aka Touch Pads)Pointing stick (aka Trak Point)JoystickMost popular input device for computer g

11、amesTouch ScreenMonitor with a touch sensitive plastic screen Typically used for restaurants, ATMs and information kiosksLight PenA light sensitive pen-like deviceTypically used for editing digital images.Scanning Devices pg 182Scanning devices convert scanned text and images into a form that the sy

12、stem unit can process.Optical ScannersAn optical scanner (aka scanner) accepts documents consisting of text and/or images and converts them to machine readable form.They work be recognizing light, dark, and colored areas that make up individual letters or images.Flatbed scanners: work like a copy ma

13、chinePortable scanners: typically a hand held device that slides across the document being scanned.Typical use is by advertising professionals who scan images and combine them with text.Bar Code ReadersBar code readers/scanners contain photoelectric cells that read bar codes.Typical uses are in groc

14、ery stores that use Universal Product Codes (UPC) which match up the product with a database entry containing product information such as price.These devices are either handheld wand readers or platform scanners.Character and Mark Recognition DevicesThese devices read special characters and marks.Th

15、ree types include:Magnetic Ink Character Recognition (MICR): used by banks for processing checks. Special reader/sorter machines process the checks much faster than the older manual methodsOptical Character Recognition (OCR): use special pre-printed characters that can be read by a light source, and

16、 are still understandable by human readers. Retail stores frequently used these types of scanners.Optical Mark Recognition (OMR) aka Mark Sensing: frequently used to score multiple choice tests marked by pencil on a form.Image Capturing Devices pg 184These focus on capturing just images rather than

17、the text/image capturing by flatbed scanners. See Making IT work and Tims Toolbox for more informationDigital CameraThe image is captured by CCD or CMOS sensors, and stored electronically where it can be downloaded to a computer.Digital Video CameraSimilar to a camcorder, only the signals are captur

18、ed in digital rather than analog format.WebCams (Web Cameras) are inexpensive digital (video) cameras that are used for video conferencing.Digitizing Devices pg 185Digitizing devices convert a sketch or figure into machine readable codeGraphics TabletsUse a special graphic surface or tablet with a s

19、tylus or pen like device to mark on it.Typically used by artists to draw digital images, or by engineers to create mechanical drawings.Digital NotepadsSimilar to Tablet PCs except users can use regular notepads and pens. The notepad is fitted on top of an electronic notepad that senses the writing m

20、ade on top.Audio Input Devices pg 185Converts sound into digital formatVoiceVoice Recognition Systems use a microphone for input, and a special sound card and software translates the analog signals into digital signals that can be processed and stored.Discrete-speed recognition systems: recognize in

21、dividual words based on their sounds. They can NOT differentiate between same-sound words (homophones) such as their, there, and theyre.Continuous-speech recognition systems: are able to distinguish between same-sounding words by evaluating the context.Dragon Systems NaturallySpeaking and IBMs ViaVo

22、ice are two well know continuous-speech recognition systems. See for informationMusicMusical Interface Digital Interface (MIDI) is a stand that allows musical instruments to connect to a computer.MIDI devices are specialized musical instruments that provide input in the form of encoded digital signa

23、ls representing musical sounds.Electronic keyboards are the most commonly used MIDI devices.Making IT Work for You Digital Photography pg 186-187This section covers the use of digital cameras, including:How to transfer your photos to your computerTouching up your imagesSharing your picturesWhat is O

24、utput? Pg 188Output is processed data or informationTypically takes the form of text, graphics, photos, or images.Output devices are any hardware used to provide or create output from the computer, for example monitors, printers, speakers, etc.Monitors pg 189Also known as display screens or screensO

25、utput is sometimes called softcopy (as opposed to printed hardcopy)FeaturesClarity: the quality and sharpness of a monitor; depends on:Resolution: measured in Pixels (Picture Elements) e.g. 1,024 x 1,280 resolution screen displays 1,310,720 pixels. The greater the number of pixels, the better the re

26、solution.Dot Pitch: the distance between pixels, typically measured in millimeters. Most monitors have a dot pitch less than 0.3 mm. The smaller the dot pitch, the better the clarity.Refresh Rate: how often the image is “re-drawn” on the monitor. Most monitors have a refresh rate of 75 Hz or better

27、(image refreshes 75 times every second). The faster the rate, the better the imageSize or Viewable Size: the diagonal length of the monitors viewing area. Smaller monitors have better image quality, but its also smaller to view.Cathode-Ray TubeMost common type of desktop monitor.Uses similar technol

28、ogy as standard TV screensAdvantage is they are relatively inexpensive and have a high quality image display.Disadvantage is they take up a lot of roomFlat-Panel MonitorAlso called Liquid Crystal Displays (LCDs) because of the technology that they use to display the image.The advantage is they take

29、up less room, and are frequently used on laptop computers.Two basic types are:Passive matrix (dual scan monitors): lower power, but poorer clarityActive matrix (TFT: Thin Film Transistor): cost more, use more power, but a much better image.Other MonitorsE-books (aka e-book readers) are PDA sized dev

30、ices that display text and graphics. These have not had a lot of commercial success, yet it is possible to download e-books onto computers.Data projectors:High Definition TeleVision (HDTV): a merger of microcomputers and television (PC/TV) offers much clearer and more detailed wide screen pictures t

31、han a standard TV (but currently at more cost). Since images are digital, they can be stored and edited.Printers pg 191FeaturesResolution: measured in Dots Per Inch (DPI), typically 300, 600, or 1,200 in modern printers. The more dots, the better the image, but the more ink that is used. Photo print

32、ing uses even higher dpi printers (2,400 & 4,800 dpi)Color capability: Black & White or colorSpeed: typically measured in Pages Per Minute (ppm). Personal printers typically print 10-15 ppm for a single color (black) and 5-10 colorMemory: most printers have on-board RAM to buffer the print so the co

33、mputer is free to do other tasks.Ink-Jet PrinterWidely used technology that sprays ink onto paper.They are relatively inexpensive, quiet, and reliable.Laser PrinterUse technology similar to a photocopierCheaper printers dont support colorOffice printers may print color, and print at high speedsTherm

34、al PrinterNot as common as Ink-Jet and Laser printersUsed for high end artwork and image reproductionOther PrintersDot matrix printers: older technology, but good for multipart formsPlotters: special purpose for making maps, images, drawingsPhoto printers: special purpose for higher quality images o

35、n photo stock.Audio Output Devices pg 193Most widely used devices are speakers and headphonesMany systems support 5.1 digital soundCombination Input and Output Devices pg 193Fax machinesAlso know as Facsimile Transmission Machines, its and older technology used to transmit a “picture” of a document.

36、Multifunction Devices (MFD)These devices combine the functions of a printer, scanner, copier, and fax into one unit.The advantage is it can save cost over buying separate units, as well as space.The disadvantage is the functionality may not be as good as separate machines, and if one goes bad, you m

37、ay need to replace the whole device.Internet TelephoneAlso known as Telephony, Internet telephony, IP telephony and Voice Over IP (VoIP) Note: IP = Internet ProtocolConvert analog voice into digital, and utilizes the Internet Protocol to send the digital signals.This technology is proving to be a po

38、pular, cost saving tool for both businesses and home users.TerminalsOlder technology often used to connect to a mainframe or host/server computer.Dumb terminals: only provide input and output to the hostIntelligent terminals (Smart terminals) can do some processing at the terminal an example would b

39、e a PC hooked up to act as a terminal as well.Network terminal (aka thin client or network computer) is a low cost alternative to an intelligent terminal. Most dont have storage capabilities, but are able to do some local processing. Sun Microsystems has tried to push this model of computing for yea

40、rs.Internet terminal (aka web terminal or web appliance) is designed to provide inexpensive, easy access to the Internet.A Look to the Future pg 196Neural Signals Inc. Creates Brain-Machine Interface.The idea behind this product is to control a computer simply by thinking about doing it rather than

41、physically controlling it.Additional material can be found at Visual Summary at a glance Input and Output pg 198InputKeyboardsPointing devicesMouseJoysticksTouch ScreensLight PensInputScannersOptical scannersBar code readersCharacter and mark recognition devicesImage capturing DevicesInputDigitizing

42、 DevicesGraphic tabletsDigital notepadsAudio Input DevicesVoice recognition systemsMusical Instrument Digital Interface (MIDI)OutputMonitorsCathode ray tubes (CRTs)Flat-panel monitors (Liquid Crystal Displays LCDs)OutputPrintersInk-jet printersLaser printersThermal printersAudio Output DevicesCombin

43、ation DevicesFax MachinesMultifunction Devices (MFDs)Internet TelephonesTerminalsKey Terms pg 2011active-matrix monitor190aka TFT monitor; laptop LCD screen type with higher power consumption, but better clarity2audio input device185microphone3audio input 185a way to convert sounds into bits that th

44、e computer can process4audio output device193speakers5bar code183printed series of lines that the computer can recognize as different characters, e.g. a UPC bar code used in grocery stores6bar code reader183specialized input device to scan information such as Universal Product Codes (UPC) on grocery

45、 items7bar code scanner183specialized input device (typically handheld) to scan information such as retail price tags8cathode ray tube monitorCRT189traditional, TV like picture tube offers high quality at a low price, but tends to be bulky9character recognition device183generic term used for a varie

46、ty of electronic character readers such as OCR , OMR or MICR10Clarity189the quality of resolution, depends on factors such as number of pixels11color capability (printer)191the ability to print in color, typically via ink-jet or laser print technology12combination device193Acts as both input and out

47、put, e.g. FAX machine, MFD, IP phone13combination key179keys such as or that are typically used in combination with another key for executing different keyboard functions14continuous-speech recognition system188a system to convert spoken words into computer useable format, using grammar rules to hel

48、p interpret the words15cordless mouse180battery operated mouse that uses wireless signals to transmit location to the computer16data projector190book sized projector for displaying computer images on a screen for presentation purposes17digital camera184camera that stores images electronically rather

49、 than on film18digital notepad185input device to allow hand written or draw images to be converted to digital format the computer can use19digital video camera184video camera that stores images in digital (computer ready) format rather than analog format20digitizing device185generic term for input e

50、quipment that converts data into digital (computer ready) format21discrete-speech recognition system188cheaper voice recognition system that only digitizes words with out taking context into consideration22display screen189generic term for any computer monitor23dot-matrix printer192older technology

51、for printers, used small pins that would strike a ribbon to form characters24dot pitch189the space between pixels on a monitor - typically less than .30 mm25dots-per-inchdpi191measurement for print quality, typically 300 x 300 up to 4800 x 4800 dpi26download 184transfer a file or data from a server

52、computer to the one you are working on27dual-scan monitor190aka passive matrix monitor, require low power and scan down the screen 28dumb terminal 195simple input (keyboard) output (monitor) device often used with mainframe systems29e-book190aka electronic book - the contents of which can be shown o

53、n a computer/e-book display30e-book reader190the device (separate hardware or a PC) and software that is used to display electronic books31facsimile machinefax194aka FAX, essentially a low resolution picture of a document that can be transmitted electronically32flat-panel monitor190aka LCD monitor,

54、often used with laptop computers, take up less space, but tend to be more expensive than CRT monitors33flatbed scanner183book sized unit used to digitize full sized documents34graphics tablet185input device to allow hand written or draw images to be converted to digital format the computer can use35

55、hard copy191generic term for printed copy (permanent copy)36headphones193small speakers that can be worn by the user37high-definition televisionHDTV190newer technology TV system offering better quality pictures38host computer 195aka mainframe computer or central computer - the main server of data an

56、d applications39image capturing device184generic term for digital cameras or digital video cameras40ink-jet printer191printer technology which sprays small drops of ink onto paper to build up the image or text of a document41input device178any type of equipment used to convert information from an en

57、d user into something the computer can process42input 178the process of taking end user information and digitizing it so the computer can use it43intelligent terminal195similar to a dumb terminal, yet it can do some processing without the host44Internet telephone194newer technology that allows telep

58、hones to send voice via Internet Protocol45Internet telephony194term used to describe the use of computer connectivity to make phone calls46Internet terminal195aka web terminal or web appliance, it provides a way to access the Internet using a television for output47IP Telephony194term used to descr

59、ibe the use of computer connectivity to make phone calls48joystick181input device for gaming49keyboard178input device to enter alphanumeric characters50laser printer192printer technology which works like a copy machine51light pen182input device for drawing images52liquid crystal displayLCD190output

60、device typically used on laptops53magnetic-ink character recognitionMICR183input technology used for processing bank checks54mark recognition device183input technology used for reading pencil marks on a form, such as a standardized test form55mark sensing183input technology used for reading pencil m