Outdoor LCD (Liquid crystal displays) systems have to cope with various outside environment effects.

1. Ambient air temperatures

2. Heat generated by high-brightness backlights

3. Direct solar radiation

This combination means that even in regions with mild average temperatures, the internal enclosure of a digital display can easily exceed safe limits. When temperatures rise above optimal thresholds, the liquid crystal layer deteriorates, rendering the display defective.

First signs of defective displays are:

1. Black spots on the LCD surface from overheating

2. Reduced image quality due to luminance loss

3. Accelerated component degradation

4. Unexpected system shutdowns or failures

Case study: Outdoor Digital Signage Network in Saudi Arabia

25 ± 2˚C
Room temperature

This is the temperature where LCD luminance output is the same as specified in tech specs. In most systems this is impossible to reach, unless an active cooling system (HVAC) is used (e.g. imotion G7 technology).

10 – 40˚C
Normal operation temperature

Normal LCD operating temperature range presents minimal drop in brightness performance output. Within this temperature range heat or cold doesn’t affect health of the LCD screens.

0 – 50˚C
Warranted operation temperature

Warranted operation range is the maximal range of inner enclosure temperatures for decent brightness performance output. All imotion systems automatically shutdown before this range is exceeded.

Find out why is thermal management becoming increasingly important?

Luminance output of LED lights depends heavily on LCD operating temperature. Lower the temperature higher the brightness performance output. Therefore, performance of outdoor digital kiosks in real life varies greatly from system to system, even if the same LCD panels are integrated.

Ambient temperature (˚C) effect on luminance output coefficient

Direct air-cooling thermal management

Benefits

• Utilizes fans for cooling airflow into the signage enclosure.

• Efficient and cost-efficient cooling method.

• Fans are speed-regulated and respond to enclosure temperature

Limitations

• Enclosure temperature is always limited by the level of ambient temperature.

Compressor based air-conditioning

Benefits

• Closed airflow loop.

• Stable enclosure temp. = best visual performance.

• Extended expected LCD lifetime (+30%).

• Can work in most demanding outdoor environments.

Limitations

• Higher initial cost

Learn how does compressor-based air-conditioning cooling technology work?

Conclusion

Cold and heat affects LCD screens. Propper thermal management lowers the impact of environment temperature to its minimum and ensures high image quality, low power consumption and slow component degradation.

To find out more, do not hesitate to contact Infinitus.