Light emitting device and illumination apparatus
First Claim
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;
whereina 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.
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Accused Products
Abstract
According to one embodiment, a light emitting device which is attached to an illumination apparatus and radiates light having a correlated color temperature of 2900 to 3600K is provided. The light emitting device includes a substrate, blue light emitting LED elements and red light emitting LED elements mounted on the substrate, and a wavelength converting unit. The red light emitting LED elements have a luminous intensity of 0.2 to 2.5 times as large as that of the blue light emitting LED elements at normal use temperature in a state where the light emitting device is attached to the illumination apparatus. The wavelength converting unit is excited by light emitted from the blue light emitting LED elements and converts the light to light having a peak wavelength within a range of 500 to 600 nm.
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Citations
11 Claims
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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:
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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;
whereina 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An illumination apparatus comprising:
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an apparatus body; a lighting circuit configured to control a light emitting device; and the light emitting device disposed on the apparatus body and configured to radiate light having a correlated color temperature of 2400 to 3600K, the light emitting device comprising; a substrate; blue 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; and 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;
whereinthe lighting circuit is 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, 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 the range of 2400K-3600K; anda luminous intensity of the red LED elements is from 0.2 to 2.5 times a luminous intensity of the blue LED elements.
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Specification