Spectral power distribution deconvolution scheme for phosphor-converted white light-emitting diode using multiple Gaussian functions

2013 ◽  
Vol 52 (5) ◽  
pp. 1016 ◽  
Author(s):  
Bong-Min Song ◽  
Bongtae Han
Keyword(s):  
White Light ◽  
Power Distribution ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Gaussian Functions ◽  
Spectral Power Distribution

scholarly journals Machine-Learning Assisted Prediction of Spectral Power Distribution for Full-Spectrum White Light-Emitting Diode

2020 ◽  
Vol 12 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Jiajie Fan ◽  
Yutong Li ◽  
Irena Fryc ◽  
Cheng Qian ◽  
Xuejun Fan ◽  
...  
Keyword(s):  
Machine Learning ◽  
White Light ◽  
Power Distribution ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Full Spectrum ◽  
Light Emitting ◽  
Spectral Power Distribution

scholarly journals Influences of Spectral Power Distribution on Circadian Energy, Visual Comfort and Work Performance

2021 ◽  
Vol 13 (9) ◽  
pp. 4852
Author(s):  
Jack Ngarambe ◽  
Inhan Kim ◽  
Geun Young Yun
Keyword(s):  
Light Source ◽  
Power Distribution ◽  
Work Performance ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Essential Element ◽  
Visual Comfort ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Spectral Power Distribution

Spectral power distribution (SPD) is an essential element that has considerable implications on circadian energy and the perception of lit environments. The present study assessed the potential influences of SPD on energy consumption (i.e., considering circadian energy), visual comfort, work performance and mood. Two lighting conditions based on light-emitting diode (LED) and organic light-emitting diode (OLED) were used as proxies for SPDs of different spectral content: dominant peak wavelength of 455 nm (LED) and 618 nm (OLED). Using measured photometric values, the circadian light (CL), melatonin suppression (MS), and circadian efficacy (CE) of the two lighting sources were estimated via a circadian-phototransduction model and compared. Additionally, twenty-six participants were asked to evaluate the said lit environments subjectively in terms of visual comfort and self-reported work performance. Regarding circadian lighting and the associated energy implications, the LED light source induced higher biological actions with relatively less energy than the OLED light source. For visual comfort, OLED lighting-based conditions were preferred to LED lighting-based conditions, while the opposite was true when considering work performance and mood. The current study adds to the on-going debate regarding human-centric lighting, particularly considering the role of SPD in energy-efficient and circadian lighting practices.

Indoor Lighting Workplaces

2021 ◽  
pp. 243-258
Author(s):  
David Baeza Moyano ◽  
Roberto Alonso González Lezcano
Keyword(s):  
Power Distribution ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Working Environment ◽  
Office Work ◽  
Light Emitting ◽  
Spectral Power Distribution ◽  
Indoor Lighting ◽  
New Criteria

Office work has so far been carried out in company buildings and was largely based on the use of paper on a horizontal surface. Due to multiple reasons, more workers are working in their homes with electronic devices. As a result, both the working environment and personal tools are changing. Since the discovery about 20 years ago of the non-visual ways of light absorption, it was known that apart from the image forming effects (IF) of light from which the criteria for correct lighting have been developed, non-image forming effects (NIF) of light exist. The discovery of NIF has enhanced researcher belief in the importance of daylighting and has raised new criteria to be taken into account for proper interior lighting. Due to all the factors mentioned above, the parameters to be met by a luminaire and its environment for proper lighting of the workstation have been modified and expanded. The rapid advance in the development of new light-emitting diode (LED) luminaires with which the spectral power distribution (SPD) can be practically created opens the door to a genuine technological revolution comparable to the invention of electric lighting around 150 years ago. The authors of this study will review the latest published studies on the importance of light in our lives, IF and NIF effects of light, the parameters which from these effects are suggested to be taken into account for a correct indoor lighting, the regulations in force on indoor lighting workplaces, and proposals to improve indoor lighting and therefore the quality of life of workers.

Modeling and Parametric Study of Light Scattering, Absorption and Emission of Phosphor in a White Light-Emitting Diode

2015 ◽  
Author(s):  
Jiaqi Wang ◽  
Jeffery C. C. Lo ◽  
S. W. Ricky Lee ◽  
Feng Yun ◽  
Mian Tao
Keyword(s):  
Power Distribution ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Optical Parameter ◽  
Optical Parameters ◽  
Peak Wavelength ◽  
Spectrum Prediction ◽  
Light Emitting ◽  
Spectral Power Distribution ◽  
Radiant Power

In this study, we proposed and demonstrated an effective approach to model and predict spectral power distribution (SPD) for a phosphor-converted light emitting diode (pc-LED). For emission and excitation, broadband diffuse transmittances of 1 mm YAG:Ce phosphor plates with different concentrations were measured by a spectrophotometer. For emission, it was found that transmittance for all wavelengths was almost identical. This result indicates that emission spectrum prediction could be simplified by simulating the radiant power of the peak wavelength only. At the peak wavelength (560 nm), our simulation results, in which optical constants were calculated by the Lorenz-Mie theory, agreed well with our measurements. For excitation, a novel transmittance measurement setup based on an LED goniophotometer was proposed to obtain the absorption coefficient. By adjusting the optical parameter in our ray-tracing model to fit measured transmittances, accurate absorption coefficients were determined. Based on our calculation and measured optical parameters, we simulated the radiant power of the blue light and yellow light of commercial white LED packages. By expanding the total blue and yellow power into linear combinations of wavelengths in both regions, we successfully predicted the SPD of our LED package. Our predicted SPD has good agreement with the measured results.

scholarly journals The Effect of Spectral Power Distribution of White Light-Emitting Diodes on Eye Fatigue

2021 ◽  
Author(s):  
Junya Sugimoto ◽  
Yukio Akashi ◽  
Yuki Hiraga ◽  
Masaru Inatani ◽  
Emi Kaga ◽  
...  
Keyword(s):  
White Light ◽  
Power Distribution ◽  
Light Emitting Diodes ◽  
Spectral Power ◽  
Light Emitting ◽  
Spectral Power Distribution ◽  
Eye Fatigue ◽  
White Light Emitting Diodes
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