US 12,245,342 B2
Illumination device including control device that varies melanopic ratio of light
Takehiro Sagawa, Okaya (JP); Yoshinori Shinohara, Chino (JP); and Naoki Nakamura, Nagano (JP)
Assigned to NICHIA CORPORATION, Anan (JP)
Filed by NICHIA CORPORATION, Anan (JP)
Filed on Oct. 20, 2022, as Appl. No. 18/048,037.
Claims priority of application No. 2021-172621 (JP), filed on Oct. 21, 2021.
Prior Publication US 2023/0126841 A1, Apr. 27, 2023
Int. Cl. H05B 45/20 (2020.01)
CPC H05B 45/20 (2020.01) 21 Claims
OG exemplary drawing
 
1. An illumination device comprising:
a light-emitting device configured to emit at least light of a first color temperature having a correlated color temperature in a range from 3500 K to 4000 K, the light having a melanopic ratio of a prescribed value within a variation range of the melanopic ratio in which a gap between a maximum value and a minimum value of the melanopic ratio at the first color temperature is 0.30 or more; and
a control device configured to control the light emitted from the light-emitting device, within a predetermined amount of time, by varying the melanopic ratio of the light by 0.3 or more within a first variation range encompassing at least a melanopic ratio value from 0.65 to 0.75, and adjusting the correlated color temperature of the light in a range from 0 K to ±500 K with respect to the first color temperature, wherein
the light-emitting device includes
a first light emitting portion configured to emit a first light, the first light emitting portion including a first light emitting element that is a nitride semiconductor having an emission peak in a range from 400 nm to 470 nm, and a first phosphor containing an alkaline-earth-metal-halogen-phosphate phosphor having a composition represented by the formula (Ca, Sr)10(PO4)6Cl2:Eu and has an emission peak at 460 nm,
a second light emitting portion configured to emit a second light, the second light emitting portion including a second light-emitting element that is a nitride semiconductor having an emission peak in a range from 410 nm to 470 nm, and a second phosphor containing an alkaline-earth-metal-aluminate-phosphate phosphor having a composition represented by the formula Sr4Al14O25:Eu and has an emission peak at 495 nm,
a third light emitting portion configured to emit a third light, the third light emitting portion including a third light-emitting element that is a nitride semiconductor having an emission peak in a range from 410 nm to 490 nm, and a third phosphor containing a rare-earth aluminate phosphor having a composition represented by the formula Y3(Al, Ga)5O12:Ce and a composition represented by the formula Y3Al5O12:Ce and has an emission peak in a range from 530 nm to 590 nm, and
a fourth light emitting portion configured to emit a fourth light, the fourth light emitting portion including a fourth light-emitting element that is a nitride semiconductor having an emission peak in a range from 410 nm to 490 nm, and a fourth phosphor containing a rare-earth aluminate phosphor having a composition represented by the formula Y3Al5O12:Ce, a rare-earth aluminate phosphor having a composition represented by the formula (Y, Gd)3Al5O12:Ce, and a silicon nitride phosphor having a composition represented by the formula (Sr, Ca) AlSiN3:Eu, and
the control device is configured to vary the melanopic ratio by adjusting a ratio between the first light, the second light, the third light, and the fourth light.