2. Heat
Most displays for industrial use have a proper temperature range from
-20° C to 70° C. To dissipate the heat occurring in the housing a cooling
system is needed. Cooling systems are divided into passive and active
cooling systems. In passive systems the heat is dissipated via the
housing or via ventilation slots. Cooling elements can be used as well,
which enlarge the surface of the housing.
Among passive systems we find heat sinks, which are thermal conductor
metals that conduct heat away from the source and dissipate it to the air,
and heat spreaders which are metal plates sometimes placed between
the heat source and the heat sink as a way to avoid heat concentration
in a concrete point and finally heat pipes, sealed tubes filled with liquid
connected with the heat source at one end and the heat sink at the
other, the cooling power of this liquids is very high.
Among active cooling systems we find the fan, which is used to
accelerate air flow in many electronic systems and liquid cooling
systems, consisting in open- or closed-loop circuits where liquid is
pumped. This systems are usually used in high performance electronics.
Cooling Systems
Active Passive
Heat Sinks
Heat
Spreaders
Heat Pipes
Fan
Liquid
cooling
3. Cold
Extremely low temperatures can also cause
damage to displays. If the display is used in ambient
temperatures of less than -20°C the screen liquid
can freeze and components can become rigid and
brittle or even burst.
A temperature fluctuating from minus to plus
temperatures close to 0°C can be problematic as
well. At this temperature surrounding moisture
condensates, causing problems in all electronic
circuits in the display.
In general LCDs react more sensitively to lower
temperatures when compared to TFTs. In LCDs the
screen build-up is significantly slower.
-20°C
0°C
4. Humidity
Humidity is evaporated water contained in the air. There are two ways humidity can occur: absolute humidity, is the objective
amount of water in the air in a concrete moment, and relative humidity is the percentage of absolute humidity compared to the
possible maximum for a concrete temperature.
Both, very low and high humidity levels can destroy a display. In the first case, relative humidity levels under 35%, static
electricity can occur, resulting in electrical discharges to the display and destruction of the whole system.
High relative humidity levels, over 80%, increase the risk of water condensation on the display components' surfaces, this leads
to corrosion and, in extreme cases, to short circuits on the device. Destruction of the electronic systems can hardly be avoided.
5. Vibration
Mechanical vibrations can influence the longevity of electronic devices as well. There are two types of transmission of
vibrations. Airborne sound, which is transmitted via vibrating airflow, and mechanical vibrations, which are transmitted via the
structure in which the display is placed.
Mechanical vibrations can destroy displays. Relevant here is the strength of the vibrations, the duration and the frequency.
Through resonances the vibrations in a system can amplify. After some time this can lead to electronic components being
shaken off and therefore to the destruction of the device.
If monitors are to be used aboard ships, where the main engine is constantly shaking, many measures are taken into account
while designing the electronics, to counter mechanical stress. Additionally, the mounting of the monitors can occur 'swimming' in
a dampening material that reduces the transmission of vibrations.
6. Cleaning and Sterility
A display should be perfectly clean at all times. Especially if
the display is equipped with a touch sensor greasy fingers
will occur very fast and will worsen the optical appearance.
But many cleaning products can harm our display. Many
cleaning agents contain acids, alcohol or corrosive liquids,
which may attack the screen, the housing or internal
components. In some monitors the display is protected by a
plexiglas pane and sometimes the housing itself consists of
synthetic materials. These materials react especially
sensitive to chemical cleaning products. Before cleaning it is
essential to read the information regarding the cleaning of
monitors.
In some places sterility is especially important, such as in
medical areas. Here the surfaces have to be sealed, and
must not have holes or joints in which germs might
accumulate and they have to be especially resistant to
various chemical cleaning agents.
7. Sunlight exposure
If a display is exposed to immediate sunlight the display content is harder to recognize. The background lighting has to be
significantly increased and additional measures, such as glass with anti-reflection coating, as well as optical bonding, should
be used.
A monitor that is exposed to direct sunlight for a longer period of time this can also develop high temperatures in the
housing. When the monitor is built into a glass lift the sunlight exposure can result in a high ambient temperature.
If a monitor with glass made of synthetic materials or a plexiglas pane is exposed to direct sunlight the synthetic materials
can fade and become brittle.
8. EMC and noise emission
If a display is exposed to immediate sunlight the display content is harder to recognize. The background lighting has to be
significantly increased and additional measures, such as glass with anti-reflection coating, as well as optical bonding,
should be used.
A monitor that is exposed to direct sunlight for a longer period of time this can also develop high temperatures in the
housing. When the monitor is built into a glass lift the sunlight exposure can result in a high ambient temperature.
If a monitor with glass made of synthetic materials or a plexiglas pane is exposed to direct sunlight the synthetic materials
can fade and become brittle.
9. What is flexyPage?
flexyPage is a modern, flexible system for multimedia presentation of process and multimedia data on displays of different sizes
and construction types. Because its powerful multicore processors, common in smartphones no active cooling is necessary. This
way, it is possible to realize very small housing dimensions. Therefore the flexyPage system is ideally suited for use in lifts, in
'Digital Signage'-applications, in building automation, as well as in mechanical engineering.
