feature
Flat panel displays
THE FIRST VIDEO WALL IN
SOUTH AFRICA
In 1995 flat panel television sets based on plasma
technology were launched. The AV industry was
soon using them as videowall displays. The main
problem with using them in video walls was the
wide frame or bezel surrounding them. Later
on "bezel less" plasmas specifically designed
for videowall were introduced. These did not
produce a seamless image and were fragile. They
were more suited to fixed installations, than to the
rental industry.
I was privileged to be involved with the installation
of, what I believe was, the first true videowall in
South Africa, and one of the first in the world.
In the mid 1980’s Electrosonic UK started
developing a videowall processing system which
became known as the Picbloc system. PIC was an
abbreviation for programmable image controller.
This new product line incorporated a “new
generation of large scale integrated circuits”.
In 2003 large LCD flat panels with a 46" screens
were launched. Although they still had large
bezels, the size made them viable for videowall
applications. This changed in 2006 with the
introduction of thin bezel LCD displays. The
next few years saw ever thinner bezels with the
slimmest at about 5mm image to image. The
introduction of LED edge-lit and direct-lit LCD
displays have made this the most popular display
technology to date.
Today's videowall processor
In the second decade of the 21st century the
most sophisticated videowall processors are cardbased and driven by powerful computers. They
are custom configured for the number of displays
and the number and type of source. Usually the
inputs are hardwired but can also be decoded
from an IP stream, using built-in decoders in the
processor.
Most dedicated videowall displays include scalers
and daisy chain inputs. This allows a video input
to be daisy-chained through the monitors,
with onboard software displaying a portion
of the image. In this way a large image can be
displayed across multiple monitors. However, this
technology is limited to a single input, with little
or no effects.
Picbloc cards originally designed in the mid 80s
The "Camel Pyramid of Light" Videowall - 1994
A software based distributed system is also
available, but requires a computer per display,
which is often fitted in an optional slot in the
display. This setup allows for multiple images to
be displayed across the display.
Videowall remains an important medium for
digital signage and control room applications.
They are most commonly found in military,
communication, surveillance and advertising
applications.
A Videowall Controller dating from the 1990s
BMW's "boxy" Videowall Monitors, early 90s
Johann Kruger, owner of Multivisio, was the first
person to invest in videowall technology in South
Africa. Upon hearing of this new technology, he
travelled to Electrosonic in the UK to see what
all the hype was about. After the demonstration
of the prototype he was so impressed that even
though the product was still in the development
phase, he immediately placed an order for a
system for an upcoming product launch.
Lourie Coetzee, who was the owner of Twin
Imports and the exclusive distributor of
Electrosonic products, arranged the importation
and logistics of this equipment. I was employed by
Twin Imports as a technician, and was responsible
for the technical aspects of the project. The
equipment arrived and consisted of flight cases
populated with 2U rack mount boxes. Each video
input required a digitiser which was housed in
a 19” 3U cabinet. Likewise each video output
required a similar box which was called a PicBloc.
Each video input required a data bus consisting of
a multicore cable linking the digitiser to the first
and subsequent PicBloc.
It was a nightmare to setup, with frequent
firmware updates. New EPROMS were shipped
via courier and had to be physically replaced in
each PicBloc. The modified TV sets were sourced
locally and prone to magnetic interference from
adjacent sets. Gaffer tape was used to insulate
each TV from the next to avoid eddy currents. A
lot of tweaking was required to get the monitors
displaying a uniform color, but, after many late
nights, the wall was finally ready for the product
launch. It was a great success and Multivisio went
on to do some of the most memorable product
launches in South Africa to date, often using
videowall technology.
PPC's interesting Videowall display at Nasrec, 1994
PROMAG
– fourth quarter 2013
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