HD Televisions

OLED televisions are the latest buzzword amongst electronic companies marketing teams. However, there is little to no information about the technology. This article takes a deeper look into OLED.

The screens are ultra-thin, making them lightweight and easy to move around. They also offer wider viewing angles that current sets. SED was once quoted as being the next technology that will arise, but after patent disputes with a company called Nano-Proprietary, it pretty much killed the technology. OLED, if it makes it, is not without its problems - Plasma and LCD are the current focus point and are selling very well, but the IP behind OLED is held tightly, so any firms wishing to invest in development has significantly increased costs, but of all the new “latest-and-greatest” tech, this one is most likely to succeed.

OLED tecnhology has been around since the 1950s. It was much later however before the first demonstration of the screens took place, in the mid-1990s. OLED technology uses organic compounds that generate light when they an electric current passes through them. If this compound is sandwiched between electrodes on a sheet of glass and it replicates the same thing - albeit only one colour. Of course, to utilise colour, the panel must be made of of red, green and blue (RGB).

One advantage of OLED over LCD is that the panels generate their own light - LCDs require a seperate light source which leads to poor color reproduction. Not only is this far better in OLED but it also leads to less power consumption. The backlighting required on LCD screens means that it is always present, wether there is 1, 100 or 10000+ pixels lit. OLED pixels however consume power only when they are lit.

Not only is the color reproduction better, but this also means the contrast is better than LCD - on the best LCD set, due to the backlighting, even the areas that are meant to be black on a screen let some light through.

The pixels on OLED’s can also be turned on/off very quickly, which is another let down on LCD screens. The response times on LCD’s varies but is generally about 1000 times slower than an OLED screen. Although 100hz refresh rates are meant to counter this, there are still often complaints of “ghosting” on LCD sets when watching fast moving content, such as sports. (Ghosting is the term used to describe artefacts left on a screen as it cannot update the picture quick enough - almost like its left a ghostly trail that slowly fades out).

The main thing consumers will be interested in is that the screens are typically ultra-thing - the 11in model from sony is only 3mm thick, the picture quality is far more advanced, with contrast levels of up to 1million:1 and there is, in theory, no reason (except cost!) why screens cannot be made that are bigger than even the biggest plasma screen available today.

The sets are not without problems. Firstly, as with all new technology, they are currently very expensive to make. The same 11in sony set costs in the region of £2500. Then main drawback however of OLED sets at the moment however is the lifespan - it is currently nowhere near ready for mass production, and the duration is no where near that of LCD and Plasma. Unless this can be sorted out quickly then the sets will not make it very far, and will be shrugged aside when the next technology buzzword appears.

Plasma TVs are an excellent choice when looking at improving your home cinema experience. They are stylish and their slim bodies will allow you much more space in your room, and can be incorporated to any design easily. Plasmas can either be placed on a stand (that are often included) or wall mounted giving you the flexibility to suit your specific needs.

How they Work
 
A Plasma display is an array of tiny gas cells which are sandwiched between two sheets of thin - but strong - glass. Each cell acts like a mini fluorescent tube, emitting ultraviolet light, which then strikes red, green and blue spots on the screen. (you may see these colors referred to as RGB elsewhere). These spots glow to build a picture.

Benefits of a Plasma TV

Picture clarity – the picture displayed is clear, crisp and vivid. Plasma screens generally have excellent contrast, quality and sharpness.
Widescreen broadcast for an astounding home cinema experience.
Excellent colour and true life detail, makes you feel like you are actually there.

 What to consider when buying an Plasma TV

The main advantage that Plasma’s have over LCD TVs is the size and cost. Once you go over the 40″ mark for an LCD cost per inch increase significantly and many beleive the picture quality to be inferior - LCDs often generate an artificial looking picture. Plasma television screens are long lived providing you with up to 60,000 hours viewing time. That’s roughly seven and a half years of watching your plasma for 24 hours a day, seven days a week. Of course, this number is often taken to mean half brightness, that is, at this point the picture will only be half as bright, so you can still go on watching your favourite programs.

Be sure to look out the the HD ready logo. HD Ready is a labelling scheme introduced by the TV manufacturers’ organisation, the European Industry Association for Information Systems (EICTA). The label means the TV has the minimum screen resolution and digital sockets to receive and display an HD picture.

Most Plasma HD TVs also have Auto format Switching. This allows you to choose which aspect ratio best suits the broadcast you are receiving. For example, showing standard (4:3) broadcasts with black bands on either side so the images aren’t stretched out of proportion. The TV will automatically adjust to the broadcasted format when using this option saving you the hassle of constantly changing when you switch channels.

Audio/video input sockets. Each time you wish to use a DVD player, set-top boxes, games consoles and other equipment, you will need a scart or AV socket for each piece of equipment. Most Plasma’s come with at least 2 scart sockets as standard. You should consider however looking for HDMI sockets to make sure your set will be future proofed, even if you dont have HDMI equipment at the moment.

Surround Sound can be an additional feature that you may wish too add by purchasing additional speakers to enhance your home system, to recreate the cinema experience. Most Plasma’s come with Virtual surround sound they mimic the effect using the two main speakers.

The very first HD Televisions started appearing around 1998. Since then, high definition television has been on the mind of every TV buyer, but for most, out of reach due to budget and lack of technological advancements. Nowadays, as uptake is more popular and manufacturing costs decrease, HD televisions are reaching the homes of millions.

But what’s the difference between HD televisions and traditional TV? Here, we explain the difference beween Analogue, digital and HD television.

Analogue: An analogue TV cannot display progressive-scan DVD or HDTV. It can show only standard-definition programmes such as those found on ordinary TV, cable, satellite or Freeview.

Digital: A digital television, or ‘DTV’, can display Freeview broadcasts from an internal digital tuner. Digital televisions may only be able to display SD pictures however.

HDTV: True high definition televisions, or HD TVs, can display SD, progressive-scan DVD, and HDTV signals. To be considered true High Definition TVs, they must have an HDCP compliant digital input, such as DVI or HDMI, as well as at least 720 lines of physical resolution. The simplest way to find out if a TV is HD compatible is to check the TV’s manufacturer specs. Some HD TV’s will accept an HD signal, but display it at a lower resolution.

Sanyo have announced they have released a waterproof 52inch HD Television.

Quite what purpose is serves in the home, im not sure. The flat-panel telly has a “marine grade” anodised aluminium frame and cabinet construction, helping to protect the innards. It could come in very handy for toddlers, parties or clumsy people alike! Sanyo even boasts that the screen’s protection against water is so good that it “can withstand low-pressure jets of water sprayed directly on the front glass”.

Sanyo have said that the TV is targetted towards commercial uses theme parks, railway stations and other open air events, although anyone interested is likely to have to fork out around £7000-£10000 for a new set.

Picture and Picture (PAP) (commonly referred to as PBP - Picture by Picture) is a related feature showing two programs side-by-side on the screen, with the sound from one program being played through the speakers, and the sound from the other being sent to headphones.

PIP stands for Picture in Picture and is a feature on some Television sets. The Television will display one program or channel (this could be a DVD, a channel from another set top box, or console etc) in full screen and at the same time, show another program as an inset in the other.

Sound is, usually, only available on the main program only.

Picture in Picture requires two independent tuners or signal sources to supply the large and the small picture. Two-tuner PiP TVs have a second tuner built in, but a single-tuner PiP TV requires an external signal source, which may be an external tuner, VCR, DVD player, or a cable box with composite video outputs. Picture in Picture is often used to watch one program while waiting for another to start, or advertisements to finish.

Panasonics latest plasma panels, the 42PZ81 & 46PZ81 now come equipped with Freesat tuners. Although more expensive than their counterparts - the 42PZ80 and 46PZ80 - the price is offset by what you’d expect to pay for a freesat tuner anyway, so you will not be out of pocket.

Like any home cinema equipment, buying a new plasma TV can be quite expensive, and you will want to look for the best available set for you. Read our getting started guide.

There are a lot of sets around with different features - many of which are confusing and daunting for a buyer with limited knowledge - manufacturers often litter adverts with a range of stickers and banners with nonsensical acronyms with no explanation - THX certified, HD ready, HDMI, DVI, PC, VGA, 1080p, 720p 1080i and the list can go on and on.

The key to buying your first set if research. You need to determine which group of sets would be best for you. Often, friends who have made purchases rave about them and pressure you nito buying the same. This may work sometimes, but peoples eyes and ears are different, as are the use of the television. Usually, Plasma TV’s are better choices than LCD for a number of reasons

Start off by making a list of the following:
Which screen size? Usually, this would be 37′, 42′ or 50′
What is your budget? - do NOT overspend.

When you have this, you will need to work out what inputs you need, and if you require additional equipment.

What inputs do you need? - If you are buying a new TV, you may want to consider checking if your existing equipment can output a better signal to the TV.
Typically, an HDMI signal is the best, followed by RGB scart. You will need to consider any input device - consoles, DVD players/recorders, Sky/Freeview boxes etc.

When you have a list of these devices, consider if any can be upgraded - within budget - for a better option, and then recheck the required connections. You may also want to look at a set of speakers for the TV if you require surround sound.

NOTE If you have a high budget, you may also want to consider an AV receiver that will upscale/upconvert the signal.

Once you have your information, you will need to check any potential Plasma TV sets in a store so you can find that is the best on your eyes. Try to avoid large chains like Dixons, as these are often poorly setup, and they will sometimes mislead potential buyers. Specialist AV stores will often show you sets through equiptment that you are using so you can find the best picture.

If you are buying a set online, look out for bundles - sometimes plasma TV sets are sold with an AV receiver and speakers in one bundle.

As a final point - Pioneer and Panasonic Plasma TV’s are usually well priced, and very good sets, you may want to consider looking at these first even if its for picture comparison.

What is the difference between standard definition (SD)and high definition (HD) - We explain in this article.

HD (high definition) is the highest resolution offered within the digital television category at the moment.

As television programming and indeed TV sets are moving from analog to digital, it’s easier to deliver movies and programming in higher resolutions.

High definition content is also more often displayed in widescreen, which is similar to how it looks in the cinema. Between SD (standard definition) and HD there’s a range of resolutions, but the easiest way to explain the difference is that a HD images hold more information than a standard definition images. This means that HD can be up to six times clearer than what you get on DVD, which lends itself to being shown on larger screens.

Resolution on a screen itself is NOT a defining factor on how good the picture quality is. That is, just because it has a higher number, doesnt mean the quality will be better. However, in order to display an HD image (as HD) a TV must be able to display certain resolutions. (see our TV resolution article).