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TFT Monitors: A question of quality

TFT Monitors: A question of quality

TFT monitors are still in the minority, but there's no question they’ll eventually take over from CRTs. ARN’s Agnes King has compiled a guide for resellers to gauge the quality of TFT monitors -- what to look out for and what to make customers aware of -- along with a quick squiz at the secretive origins of TFT LCDs.

Although it only accounts for 24 per cent of total monitors sold, thin film transistor liquid crystal display (TFT LCD) technology is set to become the next standard in computer displays. According to IT channel research firm Inform, Dell, IBM, HP and the like have seen the percentage of OEM bundles incorporating TFTs increase dramatically over the last three months. At the same time, the inclination towards “open box” tenders has seen independent monitor sales from companies such as Philips/LG, Samsung and Mitsubishi/NEC growing significantly.

Close-box procurement, whereby a hardware vendor like IBM supplies an all-in-one bundle, is progressively being phased out. "Customers are forcing the issue in tenders, asking vendors to quote without their monitors," says Joe Serra, market development manager for Samsung Electronics. He says customers are waking up to the fact that they can get a better-quality monitor for their buck if they de-bundle, so to speak. A by-product of this is that pure-play TFT vendors, such as Sony, have gained access to big-ticket sales -- like the 80,000-unit Australian Defence contract that is currently up for grabs.

Samsung, one of the three core manufacturers of TFT technology, claims to have doubled its turnover in the last two years. A large percentage of this (more than half) goes to servicing OEM agreements with brands like Dell, HP and IBM, as do all the major TFT LCD producers.

However, the strength of demand for Samsung's own brand of LCDs forced a re-organisation of its go-to-market strategy earlier this year. The vendor upset customers by handing back in excess of 100 direct accounts to its channel partners after identifying certain market segments that it wasn't reaching. "The VAR market, corporate space [500 seats and up] and the mass merchant channel have exploded in terms of growth," says Serra. "TFT is fast becoming a ‘cash and carry’ type item. You see it, touch it, pay for it and walk out the door with it."

Having said that, there's certainly an additional expense factor to consider when it comes to TFT. The average price of a LCD monitor in August, according to Inform, had a range of $1,000-$1,500, compared to an average retail tag of $350-$450 for CRTs. Meanwhile, the 17-inch and 18-inch TFT models carry a retail price of $3,000-$4,000. Most manufacturers agree that TFT will not overtake CRT for another four years, purely because of the price differentiation.

This might also be responsible for the backward proliferation of flat-screen panels. Unlike most other technologies that find broad-based acceptance in the consumer ranks before moving into the high-value corporate space, TFTs have conquered the top tiers of the pyramid first. "The flavour of the decade is occupational health and safety [OH&S] and the product lends itself quite nicely to that," says Serra. Radiation emission from the screens is virtually negligible and eye strain is dramatically reduced as an LCD does not flicker.

"Government departments could justify the expense on an OH&S basis alone," he says. Other compelling factors for corporations are the reduction in space and power consumption. Typically, an LCD screen will occupy less than one-third the desk space of an equivalent CRT monitor. In addition to running at a lower wattage, TFT LCDs generate less heat than CRT monitors, thereby reducing the cost of air conditioning and shortening the return on investment (ROI) timeframe.

And alongside all these sensible commercial benefits, there is no denying that flat-panel displays are drawing the crowds based on their damn fine appearance. TFTs are a design-conscious peripheral item, says Lewis. Incidentally, he adds that this factor will hold the grey marketeers in check for a while at least. Over the last 12 months, TFT production has been struggling to keep up with demand, which has effectively limited the grey market to rejects from branded and OEM production runs, or the odd shipment pirated on the South China Sea that ends up being flogged in the back alleys of China or Taiwan.

The opening of fifth-generation manufacturing plants, however, means that the market is experiencing its first-ever period of over-capacity. Lewis says that, like any other device, it will be a matter of price versus quality and will not immediately hurt vendors that are focused on the latter.

What will make a difference is resellers' ability to guide users through the pros and cons of the various monitors. "The end user is not yet qualified to make a choice so the reseller has an obligation to guide them," says Rudie Hess of Camcom International, importer of AG Neovo TFT LCDs. It's important for resellers to bear in mind that while any quality TFT is, by and large, better than its CRT equivalent, the customer has expectations and never forgets when they are disappointed.

Danger signs

Pixel failure The most visually disturbing occurrence in TFTs, and the least talked about, according to Hess, is pixel failure. This comes in two varieties: bright dots and black dots. The first is when the red, green, blue (RGB) sub-pixel stays constantly on; the second is when the sub-pixel simply dies altogether. Bright dots are very noticeable, Lewis says, and customers will often return a display even though they may have purchased it for half price in the knowledge that it was faulty. Black dots are less noticeable and manufacturers will tolerate a various number of these, depending on their own quality control and the price of the screen. Colloquially, TFT LCDs are separated into A-grade and B-grade batches, although within these generic grades there are up to eight different variants of quality, all relating to the number of pixel failures on the panel. Detailing what each variant actually means is difficult because there is no established standard. Hess says Mitsubishi/NEC has created a quasi-standard that most industry participants have adopted. Meanwhile, Samsung says it complies with the Australian Standards criteria, ISO 13406. No manufacturer can guarantee zero pixel failure on both black and bright dots, although Philips does offer a zero bright dot guarantee. Serra anticipates that by 2003 just about every monitor manufacturer will be trumpeting quality assurance ratios in an effort to create a unique selling point (USP). At the same time, Matt Dalton, marketing development manager of transactional desktops and monitors for HP Australia/NZ, says it's not beyond vendors to disseminate misinformation, for example by outlining specs that relate to CRT monitors but have no bearing on the performance of TFT LCD displays, like dot pitch.

Native resolution

More so than most other computing devices, TFT LCD monitors should not be purchased off spec. The picture quality needs to be tested with the naked eye because each brand operates at its own “native resolution”, a predetermined, optimum operating level that is based on the size of the screen and the corresponding clarity. At its native resolution, a screen appears at its most clear. The images and outlines are crisp and the colours vibrant. "LCD only runs picture perfect at one native resolution," explains Lewis. Any variation from this requires scaling technology to make the image larger or smaller while at the same time trying to maintain the highest clarity possible.

For this reason, Lewis believes the secret to choosing a TFT is knowing what you're going to use it for. The banking sector, for example, relies heavily on high-quality scaling software because much of the custom-built software used in the financial sector is written for VGA at 600x800 resolution. VGA is not LCD's native resolution -- the PC resolution is usually set at Super VGA 1024x768 -- so the image output needs to be scaled down.

Similarly, Camcom International is having great success importing AG Neovo's TFT LCD with an optic glass layer to protect the membrane for the medical and pre-press/publishing sector. Pre-press takes a very hands-on approach, which a TFT membrane doesn't appreciate, while medical practices have a preoccupation with antibacterial cleaning agents, which LCDs don't withstand particularly well.

Refresh rate

Measured in hertz, refresh rate is the figure given to the number of times per second that a screen is updated along its vertical axis. That is, how many times the picture on the screen changes per second. Typically, the higher the refresh rate of a display, the more stable the image appears. Generally, the higher the resolution being displayed the lower the maximum refresh rate. A good-quality indicator in monitors is the maximum refresh rate it can display at its maximum screen resolution.

Future proofing: DVI

PCs originally emit a digital signal but because CRT is an analog VGA (video graphics array) technology, the graphics card is designed to convert the digital signal into analog to display images. TFT, on the other hand, is a digital technology, which means that it has to reconvert the analog signal into DVI (digital visual interface), at least until PCs deliver digital output. All the latest up-market monitors support both VGA and DVI interfaces, according to Hess. It is a compensatory aspect until the industry realigns, although he cautions that almost all 15-inch TFTs are being released without this future proof aspect. From the manufacturer’s point of view, the cost component of including dual compliance is around $150-$200 in retail terms. "If a reseller sells an analog TFT, they are not doing justice to the customer," says Hess.

Brightness

Measured in lumens, 250 or better is ideal for brightness.

Contrast

A ratio of 400:1 or better is ideal.

Viewing angle

A TFT is something like a six or seven-layered honeycomb. Each pixel is like a hole in the matrix with two high-powered fluorescent lights shining from behind it, which is then filtered through the honeycomb by red, green and blue (RGB) transistors. The depth of the honeycomb means that from side-on the viewing angle is decreased. The degree of visibility (120 degrees horizontally and vertically is reasonably high-calibre) depends on the manufacturing technique. This is what vendors are referring to when they talk up the bezel (the rim on the cover) definition they have achieved on the panel and case.

Warranty

As with any product, the length of the warranty is a good indication of how durable the vendor believes its product to be. With TFTs, resellers should be looking for three years, keeping in mind that it includes all the common points of failure -- backlight, power supply, and pixel failure -- as well as the elements that are taken for granted, such as cables.


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