Illuminating device

#The present invention relates to a illuminating device using a semiconductor light emitting element such as a light emitting diode (LED). Particularly, the present invention relates to a white colors- or pastel colors-illuminating device where a plurality of LEDs are integrated.

#For an illuminating device such as an LED lamp using a semiconductor light emitting element, the surface of the semiconductor light emitting element is coated with a phosphor, or powder of the phosphor is contained in the resin constructing the LED lamp to practically realize other emission colors, for example white, than the original emission color from the semiconductor light emitting element. In such illuminating device, the GaN-based semiconductor light emitting element emitting blue light with a center wavelength approximately 460 nm is generally utilized. More specifically, the surface of the GaN-based semiconductor light emitting element emitting blue light is converted to the cerium-activated yttrium aluminate (YAG) phosphor emitting yellow light to obtain white color light.

#For such illuminating device using the semiconductor light emitting element, there has been such a problem that the central part of the irradiation face looks blue and a yellow ring is produced at its circumference because of passing through the blue color of excitation light, resulting in uneven coloring and non-uniform white on the irradiation face.

#FIG. 1 is a cross-sectional view schematically showing the structure of the luminescent device according to one embodiment of the present invention.

#FIG. 2 is a schematic view of an illuminating device using the luminescent device shown in FIG. 1.

#FIG. 3 is a chart showing the emission spectra of the luminescent devices in Examples 1 to 3.

#1. Luminescent device 10. Semiconductor light emitting element 20. Luminescent part 21. Phosphor 22. Sealing member 30. Visible light translucent resin 40. Mounting substrate 100. Illuminating device 110. Circuit board

#The present invention will be described in detail below, but the present invention is not limited to embodiments shown below and can be carried out in various modifications without departing from the scope of the present invention.

#The illuminating device according to the present invention comprises one or more luminescent devices, comprising a semiconductor light emitting element emitting a light with a first emission spectrum having an emission peak within a wavelength range from 350 nm to 430 nm, and a luminescent part comprising a sealing member and a phosphor absorbing at least part of light with the first emission spectrum and emitting a light with another emission spectrum different from the first emission spectrum. The illuminating device according to the present invention is, furthermore, characterized in that the excitation light contribution ratio ΔE as defined below is 0.005 or less, and the mean color rendering index Ra is 70 or more.