LED flat panel capable of seamless connection for use in lighting

Keiichi Mochizuki, Kenji Sakurai, Yoshinori Shinohara, Akihiro Tagaya, Yasuhiro Koike

Research output: Contribution to journalArticlepeer-review


We propose a light-emitting diode (LED) flat lighting panel that is capable of seamless connection by optimizing the shape of the optical elements, as well as the concentration of the scattering particles used in the diffuser material. The LED flat lighting panels that we develop can be connected to other panels while maintaining a uniformity of 90% throughout the entire surface. The results of subjective experiments reveal that the seams between the connected LED flat panels are virtually unnoticeable. We also discuss the optimal lighting designs for using the LED flat lighting panels as bracket lighting and ceiling lighting by measuring their primary optical characteristics. In particular, the unified glare rating of the seamless panel is 19.4, which corresponds to the minimum level of uncomfortable glare. Moreover, the seamless panel exhibits a luminous efficiency as high as 79.6 lm/W, which satisfies Energy Star requirements. These evaluations show that the LED flat panel is capable of providing comfortable space and lighting designs for architecture in an environmentally friendly manner.

Original languageEnglish
Pages (from-to)28-35
Number of pages8
JournalJournal of Light and Visual Environment
Publication statusPublished - 2016


  • Flat lighting panel
  • Highly scattered optical transmission polymer
  • LED
  • Seamless connection

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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