The LED video wall or LED screen is a direct vision LED
display. In it, LEDs are used not as a source of light but as separate elements
of a picture (pixels). Previously, manufacturers could not make a matrix with a
small pitch of small LEDs, so LED screens were used on large venues, for sports
scoreboards, large exhibition displays, concerts where high picture quality is
not required. However, to date, manufacturers already offer various versions of
LED displays, designed for around-the-clock use in video walls for a more
custom format, in control rooms and situational centers. Their main advantage
is high image brightness, low noise level, a thinner body, almost no visible
seam and greater color uniformity.
To opt for one of the options for the implementation of the
video wall, you must first understand whether the benefits from the
introduction of the LED video wall overlap the negative aspects, and whether
such a video wall will fully meet your objectives.
Pixel pitch
The pixel pitch primarily affects the perception of the
displayed content from a specified distance. But it is not unimportant to
consider that the pixel pitch of the video wall also affects the amount of
information that can be displayed on the screen.
Often the pixel pitch is confused with the screen
resolution. The pixel pitch measures the distance between the center points of
two adjacent pixels, and the resolution is the total number of pixels in width
and height of the screen. If you increase the diagonal of the display, the
pixel pitch also increases, provided that the overall screen resolution remains
constant.
Acceptable pixel pitch must be in the range of 0.6 to 1.3
mm. If the pixel pitch is too large, the fonts will be read worse, and the
amount of information that can be displayed on the video wall will be limited.
The pixel pitch may increase so much that viewers will be able to distinguish
individual pixels and the space between them, which will adversely affect the
ability to perceive information.
Price
On average, when calculating the cost of video walls, it can
be assumed that the LED version of a video wall with a step of 1.5 mm costs
about three times more than projection cubes of comparable size and brightness.
It is also necessary to take into account the complexity of the installation of
the LED video wall and, therefore, the cost will be higher than the
installation of projection cubes. For mounting the LED screen requires a
complex installation design.
Life time
The service life of LED screens is often much shorter
compared to the video walls of other performance technologies. For many new
models, it is significantly less than 100 thousand hours. For comparison: LED
projection cubes are designed for 80-100 thousand hours. In other words, if the
panel is designed for 50 thousand hours of work, then a threefold difference in
price will actually mean an increase in expenses by 4-6 times.
To date, the LED screen remains a very expensive technology.
Power consumption
Manufacturers of LED displays talk about low power
consumption of their devices, but you need to bring everything to a common
denominator.
Different levels of brightness can be set on LED screens and
projection cubes, so you should compare the same brightness and size. As a
result, it turns out that projection cubes consume slightly less energy than
LED displays. However, let's not forget that to display the same image, you
will need a larger LED video wall. If you use a display with a pixel pitch of 3
mm, you will need 17 times more surface area and about 27 times higher power to
display images with the same resolution as on the video cube.
Thus, the energy consumption of LED-systems in comparison
with LED projection cubes is still excessively high.
Heat transfer
Heat dissipation affects the size and cost of the required
air conditioning installation. When using the LED display on the existing
control room, the total amount of generated heat will increase significantly,
which will require replacement or upgrading of the cooling equipment. But it is
also worth noting that since the LEDs of the LED displays are located on the
outside of the screen, they do not need their own ventilation system.
Shell thickness
The undoubted advantage of LED displays is the smaller
thickness of the shell when compared with video walls based on projection
cubes. However, it should be noted that video cubes usually have front access,
while on the LED display market, only models with rear access are being
offered, which is why you have to design the mounting frame, taking into
account the distance of several tens of centimeters from the wall. Therefore,
the installation of these displays requires a distance not less and sometimes
more than the width of the video wall based on projection cubes.
Thus, today LED technology has several advantages, however,
it is necessary to take into account the calculation of the rationality of the
use of such a video wall. It should also be understood for what purposes such a
video wall will be primarily useful.
