White LEDs for solid state lighting

Niki, Isamu; Narukawa, Yukio; Morita, Daisuke; Sonobe, S.; Mitani, Tomotsugu; Tamaki, Hiroto; Murazaki, Yoshinori; Yamada, Motokazu; Mukai, Takashi

doi:10.1117/12.514069

Cited by 29 publications

(11 citation statements)

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“…White surface-mount-device (SMD) light-emitting diodes (LEDs), which are composed of a combination of a blue LED chip and phosphor, are being used for various electronic instruments, and many LED manufacturers and researchers are engaging in intensive competition to further enhance white SMD LED performance. [1][2][3] Of course, improvement of the LED chip output is an important factor in the further development of all LEDs. In addition, however, improvement of the LED packaging (PKG) light extraction efficiency η PKG is also important.…”

Section: Introductionmentioning

confidence: 99%

Optimization of surface-mount-device light-emitting diode packaging: investigation of effects of component optical properties on light extraction efficiency

et al. 2016

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An investigation of the effects of the optical properties of surface-mount-device (SMD) light-emitting diode (LED) (side-view and top-view LEDs) packaging (PKG) components on the light extraction efficiency η PKG using ray-tracing simulations is presented. In particular, it is found that the optical properties of the PKG resin and the lead-frame (L/F) silver-plating significantly affect η PKG. Thus, the effects of the surface reflection methods of these components are investigated in order to optimize the optical design of the LED PKG. It is shown that there exists peak extraction efficiency for each PKG, and the cavity angle formed by the cavity wall is important to the optical design. In addition, the effect of phosphor present in the mold resin is examined using a Mie scattering simulation. Finally, an SMD LED PKG optical design method is proposed on the basis of the simulation results.

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Section: Introductionmentioning

confidence: 99%

Optimization of surface-mount-device light-emitting diode packaging: investigation of effects of component optical properties on light extraction efficiency

et al. 2016

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“…11 An increase in temperature will affect life, luminous efficacy and peak wavelength shift. [12][13][14][15] A temperature control system was used to avoid these thermal effects. It was set to 258C for measurement and measures the spectrum Figure 4 Current regulator and PWM switch state 500 times to form an average.…”

Section: Multi-led Measurementmentioning

confidence: 99%

Parameterised LED current regulator for pulse width modulation switch delay for accurate colour mixing in multi-LED light sources

Chen

et al. 2012

Lighting Research & Technology

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Multi-LED colour mixing light sources are increasingly being used in lighting. The method used to set the dimming signal needs to accurately achieve and sustain the desired colour temperature and high colour rendering index (CRI). A pulse width modulation (PWM) signal is always used in LED colour mixing. But the PWM switch state creates a time delay in the multi-LED current regulator, resulting in a colour difference. A modified PWM signal to accurately maintain the desired colour temperature and a high CRI is derived from a parameterised LED current regulator switch state, using curve fitting. The modified PWM signal can be calculated from reconstructed coefficients of the illuminant spectrum.

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“…In recent years, the competition to further improve performance of white surface-mount-device (SMD) light-emitting diode (LED) is very intensive [1][2][3]. White SMD LEDs composed of a blue LED chip and yellow phosphor, are used for electronic instruments such as LED illuminations and liquid-crystal-display back-lights.…”

Section: Introductionmentioning

confidence: 99%

Investigation of effects of phosphor particles on optimal design of surface‐mount‐device light‐emitting diode packaging using ray‐tracing simulation

Kashiwao

Hiura

Ikeda

et al. 2018

IET Optoelectronics

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White LEDs for solid state lighting

Cited by 29 publications

References 0 publications

Optimization of surface-mount-device light-emitting diode packaging: investigation of effects of component optical properties on light extraction efficiency

Optimization of surface-mount-device light-emitting diode packaging: investigation of effects of component optical properties on light extraction efficiency

Parameterised LED current regulator for pulse width modulation switch delay for accurate colour mixing in multi-LED light sources

Investigation of effects of phosphor particles on optimal design of surface‐mount‐device light‐emitting diode packaging using ray‐tracing simulation

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