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