How to beat the heat when using TFT displays
When devices are designed for use outdoors, there are immediately several challenges to overcome and, for us, one of the most important is getting the balance right when it comes to brightness. But why? Surely, to counteract the effect of strong sunlight we simply use a TFT display with high brightness? Well, yes, but it comes at a significant cost: heat dissipation.
To reach the level of brightness needed for the great outdoors, TFT displays typically use backlight systems that produce enormous amounts of light – way more than you would ever be able to see when you’re using it. This is partly because of the structure of the TFT itself, but also the number of components between it and you – touch sensors, vandal-proof glass and front-glass coatings, for example. So, a lot of light is needed to counter the reflections of the glaring sun and (even with modern LED backlight technology) a lot of the electrical power required is converted into heat rather than light.
This heat can be substantial and highly problematic. Operating conditions, available space within the housing, cooling methods and ambient temperature can all have an impact on the internal temperature, leading it to reach – or even exceed – critical levels. This can render liquid crystal cells inoperative, accelerate component ageing and even cause complete device failure.
And, of course, when you combine this with the effects of direct sunlight, the risk of overheating is exacerbated further. Indeed, UV radiation from the sun can even cause parts of the display to decompose, bleach or weaken.
Seems like a bleak outlook, doesn’t it? However, there are plenty of mitigation strategies that can be put in place to mitigate both the effects of heat dissipation and UV damage:
- Enhancing airflow within the device housing can help dissipate heat, directing the heat flow to the outside by passive or active cooling.
- Selecting displays designed to withstand extreme temperatures can reduce the risk of overheating. TFT displays with wider operating temperature ranges (e.g. -30 to 80 deg C) are available.
- Using UV and IR filter foils, internal front cooling, and special UV-resistant bonding gels can shield the display from harmful radiation and reduce heat absorption.
Like most things, a bit of careful planning in the design stages can ensure reliability and long-lasting performance of TFT displays in outdoor environments. And, of course, our in-house designers and engineers can expertly guide you when it comes to these kinds of mitigations strategies and so much more.
Our Avnet Displays come in a range of form-factors and our display-experts are on hand to guide you in the creation of display or touch solutions that meet your requirements. Find out how Avnet Displays can propel your product innovation and get in touch today.
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