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33 Cards in this Set
- Front
- Back
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What is PAL and its standards?
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(Phase Alternating Line)
625 lines 25 frames per sec. 8 MHz bandwidth |
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What is SECAM and its standards?
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(SEquentielle Couleur Avec Memoire)
625 lines 25 frames per sec. 8 MHz bandwidth |
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What is Hue?
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The selection of color
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What is saturation?
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The intensity or vividness of a color
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What is luminescence?
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The brightness of a color
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What is Chrominance?
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Combination of hue and saturation
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What is LUMINANCE?
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A combination of Red, Green, and Blue
-Y = .3R + .59G + .11B |
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How is Y transmitted?
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Y signal for B&W recievers
Y for color receivers but only 2 signals are sent and the 3rd is derived from Y |
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What are is the color carrying signal and how is hue and saturation derived?
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3.58 MHz -phase and amplitude moduation
Phase - hue Amplitude - saturation |
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What are the HDTV standards?
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Increased Vertical Resolution (720 or 1080 lines)
Increased Horizontal Resolution (1280 or 1920 pixels) Wider Aspect Ratio (16:9) Improved Sound: digital, CD quality Improved Color and Brightness |
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HDTV vs. DTV
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HDTV – simply - higher quality television
DTV – digital television; capable of performing multiple functions e.g. interactive communication, compatibility with computers true digital is not analog TV that is converted to digital format for transmission requires digital cameras (source is digital) and digital display |
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What are the important dates for the DTV switch over?
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May 1, 1999 - Affiliates of top 4 networks in the top 10 markets must simulcast digital signal
Nov 1, 1999 - markets 11-30 July 1, 2006 - All new 25" or larger sets must have DTV tuners or be DTV-ready March 1, 2006 - Sets sized 13" or larger February 17, 2009 - Proposed shutoff date for over-air analog broadcast |
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What are the DTV standards?
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Standard definition
- 480i 704X480 - 480p 704X480 (enhanced def) High definition -720P 1280x720 -1080i 1920x1080 -1080p 1920x1080 (full or ultra hd) 8-VSB -(vestigial sideband modulation w/8 discrete amp lvls) -can divide channel into sub channels |
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What does CRT stand for and how does it work?
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(Cathode-Ray-Tube)
cathode: heated filament gives off electrons attracted to anode (positively charged) 3 beams focused and accelerated by anode R, B, and G phosphors Shadow mask: thin sheet of perforated metal in front of the screen Deflection yoke: magnetic coils used to generate fields that control movement of beams across the face of the tube |
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What does LCD stand for and how does it work?
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Liquid Crystal Display
-A light emitting from a florescent panel goes through a poralized layer that only allows the intense vibrating colors through -The light passes through a Liquid Crystal Layer that uses a varying electrical charge that react to the individual cells (RGB) and twist the light (molecules at one end of the cell end up 90 degrees from the orientation at the other end of the cell) -The varying electrical charges are then passed through another polarized layer that allows higher vibrating light waves to pass through, some that are less pass a little, and light that was not twisted at all is blocked by the polarized layer) |
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How does a Plasma display work?
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-a video card sends electrical currents through 2 sets of electrodes (vertically in the back and horizontally in the front)
-Each pixel is a cell separated with ridges called RIBS that are painted with 3 types of phosphors that glow either red, blue, ore green when energized -When the video card wants a particular pixel to glow it opens then closes the address line which in turn reacts with the atoms in the gas creating a glowing plasma -By varying the amount of current going to each cell the display can react with the different phosphors so they glow and create different hues -Combined together all of the cells create the display |
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What is DLP and how does it work?
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Digital Light Processing
Light is projected through a spinning color wheel (RGB) that rotates up to 60 time per second -The light strikes a panel of up to 1.3 million microscopic mirrors on the surface of a DLP chip -The mirrors reflect through a lens onto an ordinary projection screen -The mirrors acting as one pixel that are turned on reflect light towards the screen, mirrors that are turned off reflect light onto an absorbent surface -Hues of colors can be created by how often the mirrors turn on and off (under 20 milliseconds, creating up to 16.7 million colors - when a color pixel is turned on an electrical charge is sent to the bus that pulls the mirror near the landing pad beneath the mirror causing a 10 degree tilt |
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What does OLED stand for and how does it operate?
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Organic Light Emitting Diode
-A charge is sent from the cathode (-) to the anode (+) through organic layers -The cathode gives electrons to the emissive layer of organic molecules and the anode removes electrons from the conductive layer of organic molecules -when an electron finds a hole, the electron fills the hole (falls into an energy lvl that's missing an electron) and a photon of light is produced - The color of the light depends on the type of organic molecule in the emissive layer. Manufacturers place several types of organic films on the same OLED to make color displays -The intensity or brightness of the light depends on the amount of electrical current applied: the more current, the brighter the light. |
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What does NTSC stand for?
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National Television Standards Committee
-525 scan lines -30 fps -60 hertz refresh rate |
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What are the two types of Magnetic storage?
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Tape - sound, video, and data
Disc - data storage |
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How do VHS tapes work?
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- 1/2 inch tape
- helical or slant recording - 2.2 MHz luminance 230 lines of resolution - Placed on a 3.4 MHz carrier band using (FM) |
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What are the specs of S-VHS?
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uses a higher carrier: 5.4 MHz
higher fm modulation index can use baseband of 4.2 MHz for luminance equivalent to 430 lines of resolution separate outputs for Y and C |
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How does data storage work on a Disc?
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-by using bits, a change in polarity equals a 1 and no change in polarity equals a 0
-randomly scattered iron particles on the magnetic film are magnetized according to the various information -a coil around the read/write head is energized creating a magnet out of the iron core -the bits (line of particles) are oriented in a fashion so that they can be converted into 1's and 0's -after the data is written the read head simply passes over the disc where the polarized particles are converted into 1's and 0's so the comp. can read the data |
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What is Flash media and how does it work?
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"Solid State"
Using a Floating and Control gate (and a thing oxide layer -various voltage amounts are sent through the word line and if 50% or more voltage is present then it grounds and makes a 1. otherwise (less than 50%) it remains a 0. |
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What does DVR stand for and how does it work?
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Digital Video Recorder
-incoming signal is converted using MPEG2 encoding and sent tot he Hard Drive then is output using a decoder -varying memory 30-320 hrs of playback determined by quality -playback controls and downloadable program guides allows for various forms of recording |
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How do ipods work?
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data is stored on a hard disc then when songs or playlists are selected the songs are moved to the RAM so the songs don't skip
-then the information is converted from digital to analog, amplified, and sent to ear buds |
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How does Optical storage work?
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Using a short wavelength laser, light is projected onto a disc creating Pits and Lands
- after the disc has been written it is read through a light sensing diode that converts the lands and pits into 1's and 0's -Unlike magnetic disc storage a varying speed is needed due to the spiral pattern that the data is stored in |
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What is EFM and when is it used?
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Eight to Fourteen Modulation
Use 14-bit streams to represent 8-bit streams Each 1 bit is separated by a minimum of two 0's and a maximum of ten consecutive 0's. |
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Describe how digital audio is stored and sampled
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E.g. CD-DA bit stream (pure audio)
max bandwidth of 20 kHz sampling at 44.1 kHz 16 bits/sample for left & right=32 bits/samp 44.1 k X 32 = 1.41 Mbps EFM (Eight to Fourteen Modulation ) |
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What are the 3 methods of writing to Optical discs?
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organic dye
material that can be “burned” by high heat magneto-optical use magnetic polarity to alter light phase change material that can be heated to change reflectivity |
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What does DVD stand for and what are some of its characteristics?
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Digital Versatile Disc (DVD)
Backward compatible with CD Much more capacity than CD-ROM due to: smaller pit length tighter tracks larger surface area utilization more efficient channel bit modulation more efficient error correction less overhead a single layer is about 7 times a standard CD-ROM |
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DVD's use what kind of code?
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Regional Code
special code on on DVD movie read by player limits playback to one of 6 regions Exceptions (Region 0 discs): music, television programs, documentaries, specialist titles can be played in any DVD player |
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What is a Blue Ray Disc and how does it differ from other mediums?
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As we move up in the amount of storage space alloted on a disc, we notice the laser size gets smaller from red lasers to blue lasers.
CD- 780-nm Red laser DVD- 650-nm Red laser BD- 405-nm Blue laser -smaller track pitch allows for more data to be stored on a single disc in the future ultraviolet laser? |
