Isotropic failure kills digital signage.

So, firstly let’s understand what ‘isotropic failure’ is… It is the failing of a digital signage screen through direct sunlight affecting the screen; causing it to turn black and render it useless. As highlighted in this white paper from Samsung.

There is no come-back from this, your only option is to buy a new screen. The problem lies in the technology of the display screen; the LCD or Liquid Crystal Display. Basically this is the liquid crystals being sandwiched between two panes of glass which have electrodes connected to them. The terminology of a liquid crystal is explained as both a solid and a liquid; at the same time. The features which identify them is that the crystals maintain their shape, whilst also being able to flow and transform into other shapes. Tiny electro charges applied to the liquid crystal create patterns for letting in more or less light, thus creating an image = picture. Two main problem for LCD screen failure are both caused by temperature; too hot or too cold. If the screen is subject to very low temperatures, the liquid crystals will freeze into a solid shape – an irreversible state and then there is the opposite of extreme heat (a main cause being direct sunlight) where the liquid crystals can not hold their shape, resulting in a BLACK screen – again an irreversible state.

Image courtesy of http://www.signmedia.ca

To eliminate this problem of isotropic failure there are several points to consider:

Repositioning the screen away from direct sunlight.
This is probably the most logical option, but maybe you don’t have a choice, for example, the screen is a main feature in your shop window and at certain times of the day will be in full sunlight. Installing a canopy or shield will help to a degree, or perhaps it can be switched off at certain times of the day.

Using Specific Commercial Grade Screens.
When budgeting for a digital advertising screen, one of the main components is the screen, so size, bezel depth, quality of the picture etc. It may be tempting to cut costs and buy a consumer grade TV screen, but this will just NOT be able to cope with the rugged demands of being on for many hours at a time. Also the contrast (also known as ‘nits’) is significantly higher and of a better quality than a household TV set.

A Sun-bright or Sun-Light Readable Screen.
A digital ad campaign is of no use if a customer can not see it because of direct sunlight distorting the picture or causing blindness. Check out commercial grade screens with sun-bright/sunlight filters to alleviate such problems.

An outdoor sunlight bright display enclosure.
The steel box of the protective housing unit has many positive features; as well as protecting the screen from damage – human and environmental, it features a thermostatically controlled heater and cooler, set to an ambient temperature. As the steel box creates an oven effect, it is important to release the hot air through vents but a cooling unit will always create an even temperature. Screens are temperamental pieces of kit, which have delicate elements and are permanently damaged.

So, now you know how to avoid isotropic failure – don’t let it ruin your screen!