Posted by: Richard Williams | Posted on: | 0 Comments
The demands on outdoor digital signage can differ to other forms of digital out of home advertising (DooH). Not only does any digital advertising have to be protected from the elements if it is placed outdoors, but there must also be some consideration into what type of screen is used outside.
With flat screens there have traditionally been two choices, LCD or plasma, but a third choice in the form of back-lit LED is now available and choosing between the three can often be a difficult judgement.
The requirements for a outdoor digital signage are such that the screen needs to produce an image that is of reasonable quality regardless of the weather or lighting conditions. There has to also be a good viewing angle to ensure as many people’s eyes as possible are attracted to it.
Plasma TVs work by using a gas that is trapped between two plates og glass. This noble gas is electrically charged, turning it into turned into a plasma which produces UV light that powers the screen
Traditionally, plasmas has been seen as being able to achieve better and more accurate colour LCDs and has superior contrast ratios enabling it to produce true, deep blacks. Plasma screens also have a good viewing angle and are visible at nearly 180 degrees.
And although screen burn and image retention used to be a problem with plasma screens, this is no longer the case with modern models although the screen can be susceptible to reflection in bright rooms.
As their name suggests, LCD TVs use liquid crystal to create their image. Liquid crystal is highly sensitive to temperature change. Liquid crystals a are also rod shaped and can bend light in response to an electrical current. Each rod blinks like a shutter allowing light through or not, depending on the image being displayed.
LCDs are lighter than plasmas and this makes them easier to mount on ceilings or walls. LCD TV’s also use less power to run than plasmas. However, LCD TVs do not have the same quality of picture as a plasma and they also have a narrower viewing angle.
Back-lit LED Screens
A third choice for outdoor digital signage is back-lit LEDs. These systems are different to traditional LED TVs, often used for large screen outdoor viewing. While LED TVs use the tiny LED bulbs as pixels, a back lit LED system is a normal LCD display that has its screen boosted by a serious of LEDs that create a much brighter image.
Back lit LEDs are by far the best solution for outdoor digital signage as they have all the advantages of LCD but with a picture quality superior to that of even plasmas.