초록 열기/닫기 버튼
실외야간조명에서 광효율과 시각적 성능을 평가하는 중요 변수인 S/P((scotopic to photopic) ratio는연색특성인 color rendering index(CRI)와 상충관계로 동시 개선을 위해서는 스펙트럼 조합이 필요하다. 특히 CCT(correlated color temperature)조절형 LED조명에서는 CCT 변화과정에서 S/P ratio와 연색특성뿐만 아니라 색좌표 상의 흑체복사곡선(Planckian locus) 위를 추적하는 특성까지 고려하여야 한다. Warm white LED와 cool white LED를 조합한 CCT조절형 LED는 광효율이 높고 제어가 용이하여 많이사용되나, CCT 변화 시 Planckian locus를 벗어나 광학특성이 원하지 않는 방향으로 변한다. 본 연구에서CCT조절형 형광체 LED조명에서 Planckian locus를 벗어나지 않는 추적방법을 제시하고, 시뮬레이션된 최적결과로 LED조명을 제작하여 측정결과를 제시하였다.
The higher the scotopic to photopic (S/P) ratio is the better is the visual performance and efficiency of outdoor lightings. The S/P ratio is determined from the spectrum of light. The S/P ratio and the color rendering indices (CRIs) have a trade-off relation; therefore, optimizing them simultaneously to certain levels through spectral combinations is important. The combination of warm white (WW) LEDs and cool white (CW) LEDs is more efficient and easier to control than that of the multi-chip LEDs that are often used in CCT-controllable lighting. However, the quality of the lighting changes undesirably away from the Planckian locus during CCT tuning other than that on the two initial points of the two phosphor-converted (pc) LEDs. In this research, a method of tracing the Planckian locus during CCT tuning of CCT-tunable LED lighting composed of two pc-LEDs is proposed and is optimized through simulations so as to manufacture an actual and measurement results are also presented.
키워드열기/닫기 버튼
CCT-tunable, Phosphor-converted LED, Outdoor LED lighting, Photopic to scotopic ratio
