Office Automation,  Video over IP

Overview of display units for Video Conferencing systems

This article talks about the different display units that can be used for a Video Conferencing system to display the output (The video from the other side and any presentation). We look at CRT TV’s, LCD TV’s, Plasma display terminals and LCD projectors as the potential candidates to display the Video Conferencing output. We also discuss the pro’s and the cons of each device and see in which situations they can fit better.

Why are display devices for Video Conferencing units exciting?

¤ There is a display device for every size that you may wish to see the output in a video conferencing system.
¤ Wide range of choices are available – from the cheapest and smallest display device like a CRT TV to huge displays with plasma screens and LCD projectors.
¤ Most of the Video Conferencing units support dual display. So, if your session is going to be both video and presentation, you could have one display device for each according to their strengths.


They may be old fashioned and the cheapest of them all, but for displaying video these CRT TV’s could be the best choice. It could also display the PPT files and excel sheets, but the quality is average but still readable. But there is a limitation in the display size – Maximum 29″ Diagonal. That is the size limit for these TV’s as beyond that size, the display quality is not very good. But if you are looking for a good display unit which is less than 30″, go for the CRT TV. It is also quite economical.


While you get an LCD TV in a large array of sizes, it would be better if they are used in a Video Conferencing system in two cases: When you want your output display to be within 30″ and 42″ diagonal and when you want to display PPT and excel files effectively. Due to their good contrast ratio, they can give a great clarity especially for small fonts. But with a LCD TV be wary of one thing – the display could get blurred if you watch them beyond a certain angle from the centre. But with technology advancing each day, this is getting better. It would be better to have a demo at your conference room from all the angles before installing this one.

Plasma display device:

Plasma is a very good display device for bigger sizes – like 42″, 50″, 65″ diagonal displays. Though it is better than LCD at these sizes for displaying video, it is not very good for displaying PPT and excel pages, as the contrast is quite less. And at such big sizes, you may have the small jitters in the output of the video conferencing system blown to bigger sizes too. That means, they get noticed at such bigger sizes more easily than say, a CRT display. So, it is better to see a demo under practical usage conditions. And plasma display units also come with their own life – it may take about 10000 hours to get to half of its original brightness (after which it may not be useful) but this depends on the manufacturer – so it is better to check this point as well.

LCD Projectors:

If you want to have huge displays, and cannot afford video walls (Video wall is a technology where there are multiple cubes of display (size varies with the vendor) and all these cubes could join together to display a single output – like 2×2, 3×3 units stacked on each other and hence we get a bigger display output – but they are very costly). All you need to do is to have a white screen and project the video conference output over the screen. You can have an image of any size by adjusting the distance between the screen and the LCD projectors. Of course, the bigger the lesser clarity as it uses the same number of pixels to display the output in all the cases. But you would be surprised at how big the display can get by using a normal XGA projector and the output still look good! The lamp in an LCD projector is a consumable. They generally have a life time of 2000 hours (approximately, not guaranteed by any vendor) and they cost quite bit. LCD projectors are also good at displaying the PPT and excel output (In fact, DLP projectors are better for this, but that is a different topic altogether.

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