General Items: Tests? Questions? Anything? Reading Materials: Miscellaneous: F.Farahmand 1 / 14 File: lec7chap6f04.doc
What is output? - A computer processes the data and generates output! - Also known as Information (or processed data) - The output type depends on the HW or SW being used - Viewable, Printable, Audible, Output devices - A hardware device that can convey information to a user o Display Devices o Printers o Speakers, Handsets, etc. What is the big idea? Input (data) Processor (generates Inf.) Text Video/Graphics Audio????? Viewable Viewable visually or through some physical medium Viewable Audible Viewable What is missing? F.Farahmand 2 / 14 File: lec7chap6f04.doc
So what about DIGITAL SMELL TEHCNOLOGY? - Another aspect of Multimedia and Virtual Experience - Real or laughable? - A very challenging area of research o Where is the smell coming from? o How do they generate the smell? - The Idea: Click & Sniff - Applications: Another virtual experience; Just imagine: o Smelling the nature through your computer o Watching Smelly movies! o Smell perfumes/food/etc. before you buy them over internet - Manufacturers o Trisenx : http://www.trisenx.com/menu.html Creating customized fragrances 60 Primary aromas (odors) Uses the computer serial port o Digisents : Out of business! o Listening to the music and smelling an odor! You can buy it for $50! - Want to learn more? o http://www.time.com/time/interactive/technology/smelling_np.html What about Touching? F.Farahmand 3 / 14 File: lec7chap6f04.doc
Know the difference - Display Device: Visually conveys outputs such as text and graphics on a screen o Information is displayed temporarily (Soft Copy) - Printers: Generate outputs such as text and graphics on a physical medium (paper, film, transparency, etc.) o It generates Hard Copy and it is permanent Display Devices - Project text, graphics, video, etc. - Consists of a Screen housed in the Monitor - Projection types: o Distinctive in several ways: Technology and cost Quality (resolution) View ability Application Power usage Ergonomics - Monochrome Monitors o Black and white colors o Sometimes use Gray Scaling (one color but different contrasts) - Uses different shades of gray from white to black F.Farahmand 4 / 14 File: lec7chap6f04.doc
Lecture 8 / Chapter 6 COSC1300/ITSC 1401/BCIS 1405 10/19/2004 CRT Monitors - Cathode Ray Tube a glass tube with conductive coating - CRTs are the most common way of displaying images today o Monitors, televisions - Cathode is negative indicating the electrons - Basic Idea: o A High-speed beam of electrons flies through the vacuum in the tube and hits the flat screen at the other end of the tube o The screen is coated with phosphor, which glows when struck by the beam o The generated beam can be steered using electromagnetic fields - Each dot of phosphor consists of Red, Green, and Blue called a Pixel - Black color is created when R=G=B=0 - White color is created when R=G=B=255 - Yellow color? RG=255, B=0 What is it with the curvy looking screens? Why not flat? F.Farahmand 5 / 14 File: lec7chap6f04.doc
Field Emission Display (FED) - Fundamentally similar to CRT: But has several magnetic fields o A CRT has a single electron source addressing many pixels o An FED has many electron sources addressing a single pixel Why do you have two greens? F.Farahmand 6 / 14 File: lec7chap6f04.doc
LCD Monitors - Liquid Crystal Display Strange name (solid or liquid?) o Invented in 19 th century! o Sensitive to temperature o Easy to build! o Generating color is done by controlling each pixel separately - Flat-panel display thus smaller, lower power consumption - The basic idea: o The LC is sandwiched between two sheets made of special materials o By applying electricity the light passing through it can be blocked - Resolution is proportional to size - Some cool applications: o Calculators, what else? o Use them as picture frames! Huh? o Electronic books (would you buy one?) - Uses ClearType technology Gas Plasma Monitors - Flat-panel display devices that use Gas Plasma instead of liquid crystal - The basic idea: o By charging the gas, atoms collide and change energy levels -> generating light! - The main advantage : We can have a very wide screen - Each pixel is lit individually o The image is very bright o The image looks good from almost every angle F.Farahmand 7 / 14 File: lec7chap6f04.doc
Some basic terminologies: Response Time: Time it takes to turn a pixel on/off used for LCD monitors Electromagnetic Radiation (EMR): Magnetic field generated by the CRT monitors Energy Star Program: Building energy efficient devices Refresh Rate: Redrawing speed of the monitor (also called scan rate used for CRT monitors) Comparing different technologies: Characteristic CRT LCD Plasma Cost Low High Radiation(EMR) High None None View ability Very large Quality Good Very clear All-angles view ability Power High Low Low Refreshing and flickering Issue (75 times/s) None (on/off) None (on/off) F.Farahmand 8 / 14 File: lec7chap6f04.doc
Displaying on the computer monitor - The computer sends the signal to a video card then to the monitor - The monitor and the video card must be compatible o Agree on a set of standards: o Analog or digital o Color depth: Number of bits to store information on each pixel o Resolution: Number of dots per inch (dpi) o Memory: Needed to store information about each pixel (color resolution) - Obviously, higher color depth and resolution require more memory - Typical video standards: VGA, SVGA, Beyond Supper VGA Computer Video Card Monitor Digital signals Analog signals Basic standard: - Resolution - Number of colors and color depth - Memory Basic standard: - Resolution - Number of colors and color depth - Connections F.Farahmand 9 / 14 File: lec7chap6f04.doc
A little about TVs: - Most TVs expect analog signals (analog broadcasting) - To receive computer signals we must convert digital signals from the computer into analog - Signals must be converted to meet NTSC standard (National Television Standards Committee) - HDTV: o Expects digital signals o Much better clarity and details o lifelike pictures - 720 or 1080 lines of resolution compared to the 525 lines o Supports digital surround sound system o Offers Interactive TV features! 525 Scan lines refresh every 1/30 sec 500 dots F.Farahmand 10 / 14 File: lec7chap6f04.doc
Printers: - Output device that produces text, graphics, etc. on a physical medium - Generates a hard copy: printout o Portrait or landscape orientation - Types: o Impact: Physical contact with the paper o Non-impact: Uses spaying, heat, pressure, etc. - Printer speed: o In terms of characters per second (cps), lines per sec (lps), page per sec (pps). o Resolution (600 to 2400 dpi or more dots per inch) - Higher resolution -> better magnification ability Impact Printers: - Dot matrix printer: prints by striking the ink ribbon o Uses continuous-form paper o Speed is based on cps o Noisy and produces Near Letter Quality printouts) - Line printers o High-speed impact printer o Prints one line at time o Some support font size and style - Braille Printer o Outputs information in Braille onto paper Non-impact Printers: - Ink-jet Printers: print by spraying tiny drops of liquid (still dots!) o Produce letter quality o The resolution is based on the number of dots per inch o How is the color dried? through some sort of a heating device F.Farahmand 11 / 14 File: lec7chap6f04.doc
o They can print on anything! Photo-papers, glossy, etc. - Laser Printers o High-speed high quality non-impact printer (600-2400 dpi) o Offers high resolution o Also called page-printers (stores the entire page) o Support page-descriptive language (PDL) such as PostScript o Typically very fast (19-50 ppm) o Have large memory (16MB per page with 600 dpi resolution!) o Need a toner and works with a laser beam - Thermal Printers o Generates images by electrically heated pins against heat-sensitive paper o Not a very good quality - Portable Printers o Small lightweight printers o Can be based on different technologies (Ink-jet) o Many use USB ports (no power cord required) - Plotters o Sophisticated printers to produce high quality printouts Speakers and Headsets: - Examples: Speakers, Headsets, sub-woofer - What about subwoofers? o Tweeter, Woofer, Midrange Driver - Different technologies: o Vacuumed sealed (Acoustic), Bass Reflex, Dipole passive radiator (bi-directional) F.Farahmand 12 / 14 File: lec7chap6f04.doc
o Other output devices: - Fax Machines: o Scans a document and converts it into digital data - Transmits the image over telephone line (analog) - Receives the incoming analog signal - Converts the data into digital image - Then prints or stores a copy - Fax modem: o Sending electronic documents (such as a word document) as faxes o Multifunctional Devices: Printer, scanner, copy machine, fax machine all-in-one Want to get free-online fax (efax): http://home.efax.com/ Data projector - Takes the image from the computer and projects it onto a large screen - Basic types: LCD or DLP (Digital Light Processing Projector) o LCD: Uses its own light source to display o DLP: Offers sharper and brighter image; use tiny mirrors F.Farahmand 13 / 14 File: lec7chap6f04.doc
Terminals: - A device that performs both input and output - Types of terminals o Dumb terminals: - No processing power; transmits, receives and display the information only - Such as a Host terminal o Intelligent terminals: - Has some memory and processing capacity - Also called programmable terminals o Special purpose terminals - Perform specific tasks (cash register, bar code reader, ATM) - Types:? Point-of-sale terminals: Records purchases remotely? Automated teller machine: Self-serving banking machine F.Farahmand 14 / 14 File: lec7chap6f04.doc