Light emitting device

A light emitting device comprising:

• a light emitting element;
• and
• a fluorescent member comprising a phosphor,
• wherein the light emitting element, the phosphor, a melanopic ratio derived based on Formula (1) described below in an emission spectrum of the light emitting device, and a content percentage of a first phosphor described below with respect to a total amount of the phosphor contained in the fluorescent member satisfy any of Condition (A), Condition (B), or Condition (C) described below,
• Melanopic
• ⁢
• ratio
• =
• ∫
• 380
• 730
• Lamp
• ×
• Circadian
• ∫
• 3
• ⁢
• 8
• ⁢
• 0
• 730
• Lamp
• ×
• Visual
• ×
• 1.218
• (
• 1
• )
• wherein in Formula (1), “Lamp” is a spectral distribution of the light emitting device, “Circadian” is a sensitivity curve of an intrinsically photosensitive retinal ganglion cell being a photoreceptor located in a retina of mammals, “Visual” is a visibility curve in photopic vision of humans, “1.218” is a constant (lux factor), and in a range of a wavelength in a range of 380 nm or more and 730 nm or less, a product of “Lamp” and “Circadian” is a circadian response comprised in the spectral distribution of the light emitting device and a product of “Lamp” and “Visual” is a visibility response comprised in the spectral distribution of the light emitting device,
• Condition (A):
• a correlated color temperature of light emission of the light emitting device is within a range of 4500 K or more and 7500 K or less,
• a light emission peak wavelength of the light emitting element is within a range of 410 nm or more and 440 nm or less,
• the fluorescent member comprises
• a first phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (i) described below and a phosphor having a composition represented by Formula (ii) described below,
• a second phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (iii) described below, a phosphor having a composition represented by Formula (iv) described below, a phosphor having a composition represented by Formula (v) described below, a phosphor having a composition represented by Formula (vi) described below, and a phosphor having a composition represented by Formula (vii) described below, and
• a third phosphor having a composition represented by Formula (viii) described below,
• a content percentage of the first phosphor is within a range of 29 mass % or more and 90 mass % or less, and
• the melanopic ratio is within a range of 1.0 or more and 1.4 or less,
• Condition (B);
• a correlated color temperature of light emission of the light emitting device is within a range of 2500 K or more and less than 4500 K,
• a light emission peak wavelength of the light emitting element is within a range of 410 nm or more and 440 nm or less,
• the fluorescent member comprises
• a first phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (i) described below and a phosphor having a composition represented by Formula (ii) described below,
• a second phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (iii) described below and a phosphor having a composition represented by Formula (iv) described below,
• a third phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (v) described below, a phosphor having a composition represented by Formula (vi) described below, and a phosphor having a composition represented by Formula (vii) described below, and
• a fourth phosphor having a composition represented by Formula (viii) described below,
• a content percentage of the first phosphor is within a range of 25 mass % or more and 90 mass % or less, and
• the melanopic ratio is within a range of 0.7 or more and 1.1 or less,
• Condition I:
• a correlated color temperature of light emission of the light emitting device is within a range of 2500 K or more and 3000 K or less,
• a light emission peak wavelength of the light emitting element is within a range of 440 nm or more and 470 nm or less,
• the fluorescent member comprises
• a first phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (iii) described below and a phosphor having a composition represented by Formula (iv) described below,
• a second phosphor comprising at least one type selected from the group consisting of a phosphor having a composition represented by Formula (v) described below, a phosphor having a composition represented by Formula (vi) described below, and a phosphor having a composition represented by Formula (vii) described below, and
• a third phosphor having a composition represented by Formula (viii) described below,
• a content percentage of the first phosphor is within a range of 20 mass % or more and 90 mass % or less, and
• the melanopic ratio is within a range of 0.48 or more and 1.10 or less,
• M110(PO4)6Cl2:Eu (i)
• wherein in Formula (i), M1 is at least one element selected from the group consisting of Ca, Sr, and Ba,
• M2MgAl10O17:Mn,Eu (ii)
• wherein in Formula (ii), M2 is at least one element selected from the group consisting of Ba and Sr,
• M38MgSi4O16Cl2:Eu (iii)
• wherein in Formula (iii), M3 is at least one element selected from the group consisting of Ca, Sr, and Ba,
• Sr4Al14O25:Eu (iv)
• M43M55O12:Ce (v)
• wherein in Formula (v), M4 is at least one element selected from the group consisting of Y and Gd, and M5 is at least one element selected from the group consisting of Al and Ga,
• Lu3M65O12:Ce (vi)
• wherein in in Formula (vi), M6 is at least one element selected from the group consisting of Al and Ga,
• Si6-zAlzOzN8-z:Eu (vii)
• wherein in Formula (vii), z satisfies 0<z≤4.2,
• M7AlSiN3:Eu (viii)
• wherein in Formula (viii), M7 is at least one element selected from the group consisting of Sr and Ca.