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As PC users we have become accustomed to falling prices and rising performance and specification but even we were surprised by what has been going on in the flat screen monitor market…



It's a sobering thought that the cathode ray picture tube was conceived whilst Queen Victoria was on the throne. Comparatively little has changed since 1897 when Austrian physicist Karl Braun built the first working CRT. For more than 100 years the CRT has been the most successful, cost-effective, efficient and widely used visual display device yet devised, though that could all be about to change!


Colour LCD screens are the new kid on the block, though laptop PCs have been using them for at least the past ten years, However, apart from being horrendously expensive there have been big problems making them large enough for desktop use. Not any longer. LCD panels up to 21 inches across are now in production and improved manufacturing techniques have increased the yields to the point where one day soon LCD monitor prices could rival that of CRT based models. The Philips 151AX is a good example of how things are progressing. This is one of the cheapest monitors on the market, costing a little under £650.


That's still a fair old whack for a 15-inch screen, but barely a year ago similarly sized screens were selling for twice as much. Also bear in mind the fact that the viewing area on a 15-inch LCD screen is actually equivalent to, and in some cases larger than a 17-inch CRT display! Add to that the space-saving qualities of a flat screen display plus the reduction in power consumption and they begin to look like a rather attractive proposition. The 151AX has other virtues too, there's built in stereo speakers and a microphone and it is USB ready, though it needs an optional plug in module, costing a further £50, to make it happen.


Getting the 151AX up and running takes a couple of minutes. The requisite driver software is supplied on a 3.5-inch floppy, which Windows 9x loads when it recognises the monitor as new hardware. All display options are controlled by a graphical menu-driven on-screen display, using a set of buttons and a thumbwheel on the right side of the case. The thumbwheel can also be set to operate a volume, brightness or contrast control when used on its own.



LCDs still can't compete with CRTs in a number of key performance areas. The most obvious difference is viewing angle; the 151AX boasts a 'wide viewing angle', but the fact is the image degrades severely more than 30 degrees off centre. Resolution is still a notch or two down on similarly-sized CRTs, and the display options are much less flexible due to the way the screen is constructed and addressed. Nevertheless, the 151AX supports all VESA modes up to 1024 x 768 with a horizontal scan rate of 30 to 61 kHz


LCDs have a reputation for image lag or 'smear' that has until now ruled them out for serious moving video applications, but this is another area where big improvements have been made and although the 151AX isn't entirely lag-free, it's only really apparent on rapid motion. The very slight persistence actually works to the 151AX's advantage and the lowish vertical frequency range of 56 to 75Hz -- which could result in an annoying flicker -- causes no difficulties whatsoever.


Colour resolution is not quite up to CRT standards either, the depth and subtlety isn't there but once again the 151AX is one of the best in its class and unless you are working on colour-critical applications it shouldn't be a problem. On word processing and other office type software the quality is absolutely fine though noise is sometimes apparent in darker areas of the image. This is almost certainly due to the digital to analogue conversion process, made necessary by the video output systems used on most desktop PCs, (designed for the benefit of the all-analogue CRT display). Theoretically this will disappear with a USB connection though at the time of going to press we were not able to test this option. The less said about the speakers the better, suffice it to say it sounds a bit better than most cheap transistor radios, just…



The 151AV is a real alternative to a CRT monitor for all but the most demanding graphics intensive applications. It can easily cope with most types of desktop video operation, though we have to say this is an area where LCD panels still have some room for improvement. The main selling points, however, are the big savings on desk space, lower running costs, near zero emission and not forgetting the 'wow' factor, when people see it in action for the first time!  


How Much?                  

£645 Inc VAT)


Display size                 

15.1-inch active matrix TFT colour LCD panel


Visible display area     

307 x 230 mm


Dot Pitch                      



Max Resolution 

1024 x 768 pixels


Max refresh rate




402 (w) x 418 (h) x 176 (d) mm


5.5 kg


Philips UK, telephone (0181) 665 6350,



Features                       5

Performance                  4

Ease of use                   4

Value for money            3

Overall Rating  88%



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