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LCD Television Technology
By Brian Sheskier
What is an LCD Television?
Liquid Crystal Diode LCD’s used widely, such as in microwaves
and calculators The twisted nematic (TN) is the most
common liquid crystal used in LCD televisions today
Brief LCD History
Liquid crystals were discovered by Austrian botanist Friedrich Reinitzer in 1888
Melted cholesterol benzoate, noticed it became a cloudy liquid then cleared up as temp. rose
The liquid turned blue before crystallizing as it was cooled
Twisted Nematic Liquid Crystal
Used in most display applications today, such as LCD televisions and LCD monitors
Has a naturally crystalline structure Reacts to electric currents in particular ways,
usually by untwisting to different degrees depending on the voltage of the current it is exposed to
“Liquid” Crystal
Liquid in the sense of the crystals twistability and relative pliability in reaction to the voltage of the current it is exposed to
How do LCD TV’s Work?
Work by blocking light Sandwich a solution of TN liquid crystals
between two perpendicularly aligned sheets of polarized glass
the intensity of the light is manipulated as it passes through this structure and out the other glass panel at the other end
How LCD’s Work Cont.
Liquid crystals then untwist depending on the voltage of electrical charge passing through them
Intensity of light able to pass through second glass pane is affected
Display can switch between light and dark states
Light State/Dark State
Light State- A state of the display where the liquid crystals are fully twisted
Dark State- A state of the display where the liquid crystals are completely untwisted
Pixels
Tiny segments that make up the LCD display Manipulated to present information or form
images for viewing
Pixel Structure
Addressing
The process in which pixels are turned off (allowing the passage of light) and on (not allowing the passage of light)
Creates the image on the display for the viewer
Pixels Switched Off
-
Pixels Switched On
-
Color
Each pixel is divided into 3 sub-pixels: blue, red, and green
These sub pixels work together to produce the overall hue of the LCD’s pixel
16.8 million colors in total
Advantages of LCD TV’s
Brighter and have higher contrasts than other TV’s (no glare)
160-degree viewing angle High dot pitch = sharper and more realistic
image Cooler running temperature No static images are burned in
Advantages Cont.
Wide and colorful image High response time- time it takes a pixel to
refresh itself, which makes the image appear smoother and not jerky
Long Life Multi-uses- HDTV, regular TV, home video,
any video format is accepted
Disadvantages
Tracking motion isn’t as good as Plasma Lower contrast ratio More expensive than Plasmas Not common over 42-inches
Does anyone know how big the world’s largest LCD TV is?
Largest LCD TV
Largest LCD TV is 108” Introduced by Sharp at an electronics show
in Las Vegas
Two Links to Outside Websites
http://electronics.howstuffworks.com/lcd5.htm http://hometheater.about.com/od/lcdtvfaqs/f/l
cdfaq2.htm
ModelModel MSRPMSRP
11 Sharp LC-37G4USharp LC-37G4U $5,999$5,999
22 Sharp LC-32G4USharp LC-32G4U $4,499$4,499
33 Toshiba 32HL83PToshiba 32HL83P $4,499$4,499
44 Sony KLV-23HR2Sony KLV-23HR2 $2,699$2,699
55 Panasonic TC-Panasonic TC-32LH132LH1
$4,499$4,499
66 Sharp LC-20B4U-Sharp LC-20B4U-SS
$2,199$2,199
77 Toshiba 26HL83PToshiba 26HL83P $3,299$3,299
88 Sharp LC-26GA4USharp LC-26GA4U $3,299$3,299
99 JVC LT-26WX84JVC LT-26WX84 $2,999$2,999
1010 Sony KLV-Sony KLV-30XBR90030XBR900
$4,999$4,999
References
www.about.com www.howstuffworks.com www.plasmatvbuyingguide.com www.wikipedia.org
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