Patents Examined by Sileho Roy
  • Patent number: 7294956
    Abstract: The semiconductor light emitting device is composed of a combination of a near ultraviolet LED and a phosphor layer including a plurality of phosphors for absorbing near ultraviolet emitted by the near ultraviolet LED and for emitting fluorescence having an emission peak in a visible wavelength region, and the phosphor layer includes four kinds of phosphors, that is, a blue-based phosphor, a green-based phosphor, a red-based phosphor and a yellow-based phosphor. Thus, lowering of luminous flux derived from red-based light with low luminosity is compensated by yellow-based light with comparatively high luminosity, and the resultant white-based light can be well color balanced, and hence, a semiconductor light emitting device emitting white-based light with high luminous flux and a large Ra can be obtained.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: November 13, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshihide Maeda, Shozo Oshio, Katsuaki Iwama, Hiromi Kitahara