LCD , LED AND PLASMA TV

INTRODUCTION

Television (TV) is a telecommunication medium for transmitting and receiving moving images that can be monochrome (Black and White) or colored, with or without accompanying sound.

The word Tele is a Greek word meaning Distant and Vision meaning Sight.

The components used in old TV's are essentially very similar to the components used in modern TV's; that is, they perform the same function as their modern counterparts. Where they differ greatly however, is in their size.

There are different types of TV depending upon the display device used. Display DeviceA display device is an output device for presentation of information in visual form. When the input information is supplied as an electrical signal, the display is called an electronic display.

Types of Display DevicesCathode Ray TubeFlat - Panel Display

Flow chart

CATHODE RAY TUBE Thecathode ray tube(CRT) is acontaining an (a source of electrons) and ascreen, with internal or external means to accelerate and deflect the electron beam, used to create images in the form of light emitted from the fluorescent screen.

FLAT PANEL DISPLAYFlat panel displays (sometimes referred to as flatscreens, which more technically mean screens with fully flat front surfaces) encompass a growing number of technologies. They are far lighter and thinner than traditional and that use (CRTs), and are usually less than 10 centimetres (3.9in) thick.

Types of Flat panel Displays

Emissive display devicesPlasma panelsElectroluminescent displays

Non emissive display devicesLCD

LIQUID CRYSTAL DISPLAY(LCD)Liquid-crystal display televisions (LCD TV) are sets that use technology to produce images

Produces colored image by selecting filtering a white light

Thinner and lighter than of similar display size

The concept of LCD was 1st brought up by Philips

LIQUID CRYSTAL DISPLAYLiquid Crystal a stable phase of matter characterized by anisotropic properties without the existence of a 3-dimensional crystal lattice generally lying between the solid and isotropic (liquid) phase.

ISOTROPIC ANISOTROPIC(Liquid Crystals have orientational order)

(Liquids and gases)

LIQUID CRYSTAL MODEL

Unique Properties of Liquid Crystals The orientation of Liquid Crystals can be affected by

PressureTemperatureElectrical Field

LCD PreparationChecking the ITO GlassRubbing the PVA to create an alignment layerRemoving the PVA at one edgePlacing the Saran Wrap SpacersApplying the Liquid CrystalPlacing the Polarizers at 90

Cross-sectional view

LCD TechnologyElectrical-fieldNOT AppliedLight IS transmittedElectrical-fieldIS AppliedLight NOT transmitted

LCD PIXEL

PROPERTIES OF LCD DISPLAY Light weight (typ. 1/5 of CRT) power consumption (typ. 1/4 of CRT) No electromagnetic emission Large screens (>20 inch) on desktops Completely flat screen - no geometrical errorsCrisp pictures - digital and uniform colors Fully digital signal processing possible Low luminance (typ. 200 cd/m2)

Led-Tvs An LED-backlit LCD display is a flat panel display that uses LED backlighting instead of the cold cathode (CCFL) backlighting used in other LCD displays. While not an LED display, televisions using this display are called "LED TV" by some manufacturers and suppliers.The use of LED backlighting allows for a thinner panel, lower power consumption, better heat dissipation, a brighter display, and better contrast levels

Difference between LCD and LEDProduce images with greater dynamic contrast;With edge-LED lighting can be extremely slim, some screens less than half an inch (0.92cm) thick.Offer a wider color gamut when RGB-LED backlighting is used.Produce less environmental pollution on disposal;Are more expensive;Have typically 20 to 30% lower power consumption;Are more reliable.Can allow a wider dimming range.

PLASMA TV Plasma display screens are made from glass, which reflects more light than the material used to make an LCD screen. A plasma display panel (PDP) is a type of common to large TV displays 30 inches (76cm) or larger. They are called "" displays because the technology utilizes small cells containing Capable of producing deeper blacks allowing for superior

PLASMAPlasma is a similar to in which a certain portion of the particles are .

Heating a gas may its molecules or atoms (reduce or increase the number of in them), thus turning it into a plasma, which contains particles: positive and negative electrons or ions.

In the , plasma is the most common . Some common plasmas are and . PLASMA LAMP

PLASMA DISPLAY PANELS

Cross-sectional view

FUTURE TECHNOLOGY OF TVOLED (Organic light emitting diode)Sony introduced this technology in 2008

It doesnt required backlighting

Allow less power consumption

Screen are so thin and so flexible that one can roll them up like a carpet

We will have OLED based TV in our living room around 2015

SURFACE CONDUCTION ELECTRON (SED)Better quality picture.

Power efficient.

Long lasting

Canon the originator of SED

LASER TV The laser technology claims that the technology will allow displays with a richer, more vibrant colour palette than the conventional plasma, LCD or CRT displays They also claim the displays will: be half the weight and cost of plasma displays

require around 25% of the power required by Plasma displays

be very thin like plasma and LCD displays are today

3D TV It creates an ability to present viewer with two slightly different images

One for the left eye and one for the right eye

Auto-stereoscopic display is being used

HALOGRAPHIC TV Image project outward from TV as they appear to float inmid-air. One could walk around a specific object and look it from behind or can put himself in middle of the action.

References :-en.wikipedia.org/wiki/Plasma_(physics)

www.howstuffworks.com ...

en.wikipedia.org/wiki/LED-backlit_LCD_display

www.slideshare.net/Firedemon13/plasma-8164874 - United States

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