With high-efficiency phosphor converted amber LEDs available and demonstrating proven lifetime characteristics, Forge’s ECS stand is the perfect place to explore their benefits.

The professional display and signage sector has relied on amber and yellow LEDs for many years. These technologies enable robust, reliable dot-matrix panels and provide sufficient brightness to remain visible in outdoor conditions.

Given these strengths, amber and yellow LEDs are widely used in transport infrastructure across the globe—in road, bus, rail and terminal signage. The platform of choice for these applications has long been aluminium indium gallium phosphide (AlInGaP) compound semiconductors. Having effectively become the industry standard, AlInGaP LEDs have served the sector well for almost 30 years.

However, AlInGaP comes with drawbacks. They are relatively expensive to produce and their narrow wavelength emission spectrum means that tight production control is required to avoid colour inconsistencies such as mismatched patches in displays.

Despite these limitations, AlInGaP remains the dominant technology. However, an alternative has now emerged, developed initially for the lighting industry—phosphor converted amber (PC amber).

Manufactured in the same way as white LEDs, PC amber LEDs use a blue indium gallium nitride (InGaN) semiconductor to produce light, which is then down-converted to amber by a phosphor coating. This approach offers several advantages. It is more cost-effective, benefiting from the economies of scale in general lighting. It also provides higher efficiency and a broader spectral emission, improving colour consistency.

The use of PC amber is already widespread—almost all vehicle turn indicators now use it. However, its uptake in professional displays has been limited by one key issue: phosphor degradation over time.

As phosphors degrade, light output diminishes and colour can shift. In short-use applications like vehicle indicators (typically operating for ~1000 hours over their lifetime), this isn’t a concern. However, for professional signage, which often operates continuously for years, degradation is a serious issue.

Forge, active in the LED signage and display market since the 1990s, has tackled this problem head-on. By developing tailored LED semiconductor and phosphor combinations, the company has achieved the long service life required for professional applications. These LEDs have undergone rigorous life testing under globally recognised standards—IESNA LM-80-20 and TM-21-21.

The result, a range of PC amber LEDs capable of delivering lifetimes exceeding 10 years, with minimal degradation or colour shift.

This investment in R&D opens the door for the signage and display industry to embrace PC amber, unlocking higher efficiency, better consistency and lower lifetime costs.

www.forge.co.uk