Patent ID: 8820950
Filing Date: 2014-09-02
Classification: F21K,F21S,F21Y,G09G,H01L,H05B

Abstract:
1. A light emitting device which is attached to an illumination apparatus configured to control a light, the light emitting device configured to radiate light having a correlated color temperature of 2400 to 3600K, the device comprising: a substrate; blue light emitting diode (LED) elements mounted on the substrate; red LED elements mounted on the substrate, the red LED elements having reduction rates of luminous intensity according to temperature rise that are higher than reduction rates of luminous intensity of the blue LED elements according to temperature rise; a wavelength converting unit configured to be excited by light emitted from the blue LED elements and convert the light emitted from the blue LED elements to light having a peak wavelength within a range of 500 to 600 nm; and a lighting circuit configured to control current to both the blue LED elements and the red LED elements to perform dimming control such that a ratio of a current to the blue LED elements to a current to the red LED elements is constant when the light output is controlled at less than full intensity; wherein a luminous intensity of the red LED elements is from 0.2 to 2.5 times a luminous intensity of the blue LED elements; and when junction temperatures of the blue LED elements and the red LED elements are 120° C. or lower and the light output is dimmed from full intensity to less than full intensity, a color temperature rises, as an intensity of the red LED elements increases relative to the blue LED elements, within a range of 2400K-3600K.