DIFFERENT TVs AND THEIR CONFIGURATION PRESENTED BY:- Jayraj Chudasama( ) Bharat Mundhara ( ) GUIDED BY:- Prof. Rohit Parmar Department of Electronics and Communication Engineering G. H. Patel College of Engineering & Technology Vallabhvidyanagar, Gujarat –

Introduction to LED TV LED TV is just an LCD TV, which uses light emitting diodes [LED] as the light source to light up the screen, unlike LCD TVs, which use Cold Cathode Fluorescent Lamps [CCFL]. The material used to construct LED is aluminium-gallium- arsenide. An LED is basically a teeny-weeny light bulb. Unlike the regular light bulbs, it doesn’t have a filament to burn out. LEDs have a really long life span compared to a regular light bulb or fluorescent lamps. This is one of the main differences between Plasma and LED TV.

It can produce deeper blacks and therefore higher contrast ratio and sharper picture than Edge-lit models. Advantages: Disadvantages: They are slightly thicker than Edge-lit LED TVs.

LEDs can be laid in different configurations behind an LCD screen and uses either white LEDs or RGB [Red, Green, Blue]. White LEDs can be further configured into three different ways: Full Array LED TV RGB Dynamic LED TV Edge-Lit LED TV.

RGB Dynamic LED TV : This method of backlighting allows dimming to occur locally creating specific areas of darkness on the screen. This means you see truer blacks and much higher dynamic contrast ratios.

Three primary colors (R- G- B-) emitted by white LED backlight are able to give a color gamut represented by 110% NTSC. LED backlight is obtained by mixing green, red and blue in the correct ratio (64%G, 28%R and 8%B).

Edge-LED TVs:- A very few hand select models are available in this model from Sony, Samsung and LG. Edge-Lit LED TVs have LEDs arranged along the four sides of the TV, instead of the entire screen. A special light guide is used to spread the light uniformly across the screen. Two different types of Edge-LEDs are available: Edge-Lit LED TV [With local dimming] Edge‐Lit LED TV [Without local dimming]

Edge-Lit LED TV [With local dimming] In this model, local dimming is possible in certain zones of the screen without placing LEDs behind the screen. Picture is sharper than the Edge-lit model without local dimming but not at par with full array models.

Can produce deeper blacks and achieve higher contrast ratio than Edge-Lit models without local dimming. Thinner profile than full array model Advantages: Disadvantages: Picture is not as sharp as full array models.

Edge-Lit LED TV [Without local dimming] This model is same as Edge-Lit with local dimming except that local dimming is not possible.

Thinner design than full array models. Weighs less than full array models. Advantages: Disadvantages: Contrast ratio is not as good as full array, because local dimming is not possible. Lighting may not be uniform across screen

Difference between LED-backlit and CCFL-backlit LCD

Compared to CCFL (cold cathode fluorescent)-backlit LCDs, LED-backlit LCDs: Produce images with greater dynamic contrast Can be extremely slim (some screens are less than 0.5 inch (0.92 cm)) thin in edge-lit panels. Offer a wider color gamut (when RGB-LED backlighting is used) Produce less environmental pollution on disposal Have (typically) 20- to 30-percent lower power consumption (and longer lifespans) Run significantly cooler Are more reliable. Allow a wider dimming range. Are significantly lighter, often as much as half the total chassis and system weight of a comparable CCFL. LEDs have better performance parameters than CCFL in terms of voltage of operation, frequency of operation, reliability, low temperature operation and image quality on LCD screen.

Comparison of Plasma TV and LED TV:

LED TVPlasma TV ThicknessLED edge backlit LCD TVs are thinner than CCFL LCD TVs. Often less than 1 inch. Minimum 1.2 inches Power consumptionLED-lit LCD TVs consume less power around 70% compared to plasma TVs Consumes slightly more power than an LCD TV. Modern plasma displays receive high Energy Star (US) ratings. Screen size Up to 90 inches42 inches and above Burn-inBurn-in is very rare Burn-in is rare on newer plasma TVs with anti-burn-in features, but was somewhat common on old plasma TVs.

LED TVPlasma TV Life spanAround 100,000 hoursAround 20, 000 – 60,000 hours Viewing angle The brightness and color on LCD TVs shift noticeably over the screen and depending on viewing angle Plasma TVs look the same from almost any angle Contrast Ratio (difference between the deepest black compared to the brightest white) Worse than plasma TVs. All LCDs produce brighter whites, but brighter blacks as well. Locally- dimmable LED backlit LCD TVs can mitigate this to improve contrast ratios. Better than LCD TVs. Plasma TVs produce darker blacks and somewhat dimmer whites, but most TVs are not set bright enough to hurt contrast ratios. WeightLighter compared to plasma TV Heavier compared to LED-lit LCD TV

LED TVPlasma TV Brightness and colourBrighter than plasma or OLEDNot as bright as LED-lit LCD. Screen ThicknessThinner than LCD, plasmaThicker Energy Use Less for dynamically backlit LCD TVs, about as much for statically backlit ones. Generally more. Running Temperature Dynamically lit LCD TVs dissipate less heat compared to plasma TVs, LED-lit LCD TVs dissipate less heat than even other LCD TVs. Plasma TVs generally dissipate more heat than LCD TVs Screen glare Antireflectively coated (matte finished) LCD TVs have less glare than glossy LCD TVs. Plasma TVs have more glare than LCD TVs in brightly lit environments due to their thick front glass's internal reflections ManufacturersAll TV manufacturing companiesPanasonic, LG, Samsung

OLED (Organic Light Emitting Diodes) TV:

An OLED TV screen uses a new display technology called OLED (Organic Light Emitting Diodes). OLED televisions are brighter, more efficient, thinner and feature better refresh rates and contrast than either LCD or Plasma. OLED TVs deliver the best picture quality ever.

OLEDs are made by placing thin films of organic (carbon based) materials between two conductors. When electrical current is applied, a bright light is emitted. The OLED materials emit light and do not require a backlight (unlike LCDs). Each pixel is a small light-emitting diode.

Advantages: Faster refresh rate, better contrast and better colour reproduction OLED TVs are just 4 mm thick, and some OLED panel prototypes are merely 0.3 mm thick. Better viewing angle - almost 180 degrees.

OLEDs draw less power, and contain no toxic metals (that's almost true - OLEDs contain a trace amount of Iridium, a non-toxic heavy metal) OLED panels can potentially be made flexible or transparent

Disadvantages: -> Lifetime - While red and green OLED films have longer lifetimes (46,000 to 230,000 hours), blue organics currently have much shorter lifetimes (up to around 14,000 hours) -> Manufacturing - Currently, manufacturing is more expensive than LCDs -> Water can easily damage OLEDs ->OLED screens are even worse than LCD in direct sunlight ->Overall luminance degradation ->Limited market availability

Applications: Televisions Cell Phone screens Wrist Watch Computer Screens Bendable Devices Portable Device displays

Future scope and available devices: Data glass GPS system Curved OLED displays Future concept: Nokia concept OLED scroll up Laptop