Cold weather LCD | TFT Displays with heaters
Cold weather LCD, such as the TFT display are a popular options for products that require a bright color graphical display. This includes laptops, medical equipment, ruggedized electronic devices, cell phones and GPS devices. This is because the majority of TFT displays can operate as low as -30C (-22F). If your product will be operating in a harsh, cold environment where temperatures fall below -30C you may need to add a LCD heater to your TFT display.
Construction of a TFT LCD heater:
A TFT heater operates in the same manner that heat tape keeps a water pipe warm.
The basic construction of a TFT heater is a layer of transparent film that is electrically conductive and is applied to the glass. The film provides an even flow of constant heat.
The heater film is applied to either the front or the back of the TFT module and uses an adhesive to hold it in place.
Power requirements of a TFT heater
Heater film applied to a TFT module consumes an estimated one to two watts of power per square inch. Operating voltage can range from 12 volt to 28 volts. This can be very power consuming and is not recommended for battery powered products.
Concerns with a TFT heater
There are two items to take into consideration when adding a heater to your cold weather LCD display.
First, most TFT heaters are custom, which means there is a one-time tooling fee that can start around $5,000 on up. This tooling cost includes the redesign of the PCB and bezel. Click here for more information on our custom LCD heater solutions.
Second, a heater is a power hungry device. It may not need to be active all the time, but when on, it can drain a battery in a short time.
Alternatives to a TFT display heater
If power consumption or tooling cost is a concern there are a few alternatives to adding a heater to your TFT display.
Insulate your TFT Display
Many times adding a layer of insulation to your TFT will allow it to operate without a heater. One major improvement is to reduce the amount of wind that blows across the display. Install the TFT inside a sealed case.
Convert from TFT to an OLED
Another possible solution is to convert your TFT to an OLED (Organic Light emitting Diode). OLEDs can offer a sharp contrast and multiple colors with the advantage of operating down to -40C. An advantage of OLED’s over TFT’s are that they are thinner and require less power. One downside is that they cannot be manufactured in large sizes at an affordable cost.
Panasonic has released a 56 inch OLED TV at the 2013 CES show, but it is not in production. I do not know the estimated cost of this, but have read that it is very, very expensive.
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