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LED chip maker Epistar Corp of Hsinchu Science-based Industrial Park, Taiwan says that it has developed a warm-white LED with a a correlated color temperature (CCT) of 3000K, a color rendering index (CRI) of 80, and a luminous efficacy of 80lm/W.
Picture: Sample packaged with Epistar’s newly developed chips.
The firm says that it has been developing technology that can simultaneously achieve high CRI and high efficacy (the two main performance metrics in the lighting industry using white LEDs). Usually, these two metrics work against each other and their combination becomes a trade-off, especially for warm-white LEDs. To achieve better CRI, red phosphor is needed to compensate for the shortage in the red spectrum. However, the efficacy of existing red phosphor is low (about 40lm/W), resulting in low overall efficacy.
Epistar’s new LED includes one or several high-voltage monolithically integrated DC multiple-chip arrays combined with a bridge structure for an AC drive. Several red LED chips are also incorporated into the design. With the help of the high-brightness red and blue LEDs, the overall efficacy is increased while high CRI is achieved at the same time.
Picture: Layout of the blue monolithically integrated multi-chip array.
The firm adds that it expects to demonstrate a new product in fourth-quarter 2009 with a CRI of more than 80 and efficacy of 100lm/W at a CCT of 3000K.
Epistar’s announcement follows South Korean LED maker Seoul Semiconductor Inc saying in late August that it had launched the Acriche A4 AC-LED, which has a CCT of 3000K, a CRI of 85, and luminous efficiency of 75lm/W.
Search: Epistar Warm-white LEDs
Visit: www.epistar.com.tw