Abstract
Laser-driven phosphor conversion (PC)-type white light sources are receiving a great deal of attention in next-generation high-intensity lighting and display technologies. Laser lighting is attracting attention for its functions, such as energy saving and light distribution control. However, the PC-type white light source has problems with color control and thermal quenching. Thus, monochromatic light mixed- or color mixed (CM)-type white light sources are promising, but there is a problem with their color rendering properties. We investigated the CM-type white light sources that mix four colors (blue, green, yellow, and red). We have improved the color rendering index (CRI) of a four-color mixed laser. By maximizing the value through combining the wavelength of four colors and each laser output ratio, the average CRI Ra and the special CRI R9 can be obtained when the color temperature used in general lighting is approximately 5000 K. The color rendering property was predicted by the combination of laser output ratios, and a light source with an Ra of 80 or more and R9 of 94 was obtained experimentally. At the same time, we were able to demonstrate the high luminous efficacy of radiation.
Similar content being viewed by others
References
Yagasaki, K., Minemoto, H., Fujioka, K., Fuji, H., Yamamoto, K.: The 9th laser display and lighting conference, digest of technical papers, LDC-11-04 (2020)
Neumann, A., Wierer, J.J., Jr., Davis, W., Ohno, Y., Brueck, S.R.J., Tsao, J.Y.: Four-color laser white illuminant demonstrating high color-rendering quality. Opt. Express 19, A983–A990 (2011)
Kinoshita, J., Aizawa, H., Takamori, A., Yamamoto, K.: The 23rd international laser display workshops in conjunction with asia display 2016, digest of technical papers, PRJ1-4 (2016)
Manabe, Y., Ishino, M., Fuji, H., Kinoshita, J., Fujioka, K., Yamamoto, K.: The 10th laser display and lighting conference, digest of technical papers, LDC-5-03 (2021)
CIE: Method of measuring and specifying color rendering properties of light sources, CIE standard 013.3-1995 (Commission Internationale de l’Eclairage) (1995)
Ohno, Y.: Spectral design considerations for white LED color rendering. Opt. Eng. 44(11), 111302-1–9 (2005)
Moreno, I., Contreras, U.: Color distribution from multicolor LED arrays. Opt. Express 15(6), 3607–3618 (2007)
Malacara, D.: Color Vision and Colorimetry. SPIE Press, Bellingham (2002)
Wyszecki, G., Styles, W.S.: Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd edn. Wiley, New York (1982)
Ohno, Y.: Radiometry and Photometry Review for Vision Optics, in Handbook of Optics (Vol. III, 2nd ed.), Bass, M., Enoch, J. M., Van Stryland, E. W., Wolfe, W. L., (eds.) (McGraw-Hill, Cambridge, 2001)
https://www.osram.us/cb/tools-and-resources/applications/led-colorcalculator/index.jsp
Moreno, I., Ramos-Romero, I.R.: Light spectrum for maximum luminous efficacy of radiation and high color quality. Proc. SPIE 10745, 107450P–1 (2018)
Phillips, J.M., Coltrin, M.E., Crawford, M.H., Fischer, A.J., Krames, M.R., Mueller-Mach, R., Mueller, G.O., Ohno, Y., Rohwer, L.E.S., Simmons, J.A., Tsao, J.Y.: Research challenges to ultra-efficient inorganic solid-state lighting. Laser Photon. Rev. 1, 307–333 (2007)
Murphy, T.W.: Maximum spectral luminous efficacy of white light. J. Appl. Phys. 111(104909), 1–6 (2012)
Hung, P.-C., Tsao, J.Y.: Maximum white luminous efficacy of radiation versus color rendering index and color temperature: exact results and a useful analytic expression. J. Disp. Tech. 9(6), 405–412 (2013)
Acknowledgements
The authors would like to thank Dr. A. Takamori for his useful discussions and technical support in the measurements.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Manabe, Y., Ishino, M., Fuji, H. et al. Improvement of color rendering index of BGYR laser illuminants. Opt Rev 29, 267–275 (2022). https://doi.org/10.1007/s10043-021-00717-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10043-021-00717-w