Light source device and light emitting device
Provided is a light source device including: at least one light emitting element of at least one type; at least one far-red phosphor that, when excited by output light from the light emitting element, emits light having a peak in a wavelength range of 680 nm or more to less than 780 nm; and at least one phosphor that, when excited by the output light from the light emitting element, emits light having a peak in a wavelength range different from the wavelength range of the light emitted from the far-red phosphor. The spectrum of light emitted from the light source device has characteristic A below. This light source device has sufficient emission intensity over the entire visible range, i.e., over a wavelength range of from 400 nm to 750 nm inclusive. Characteristic A: The ratio of a minimum emission intensity to a maximum emission intensity in a wavelength range of from 400 nm to 750 nm inclusive is 20% or more.
1. A light source device comprising: at least one light emitting element of at least one type; at least one far-red phosphor that, when excited by output light from the at least one light emitting element, emits light having a peak in a wavelength range of 680 nm or more to less than 780 nm; and at least one phosphor that, when excited by the output light from the at least one light emitting element, emits light having a peak in a wavelength range different from the wavelength range of the light emitted from the far-red phosphor,
wherein the spectrum of light emitted from the light source device has the following characteristic A:
characteristic A: the ratio of a minimum emission intensity to a maximum emission intensity in a wavelength range of from 400 nm to 750 nm inclusive is 20% or more.
2. The light source device according to claim 1 , wherein the at least one far-red phosphor comprises (Ln 1-x Cr x ) 3 M 5 O 12 (where Ln is at least one element selected from Y, La, Gd, and Lu; is at least one element selected from Al, Ga, and In; and x is a number satisfying 0.005≤×≤0.2).
3. The light source device according to claim 2 , wherein, when light is emitted from all of the at least one light emitting element mounted on the light source device with no phosphors mounted thereon, the light emitted has a peak wavelength in a first wavelength range of 380 nm or more to less than 420 nm and a peak in a second wavelength range of 420 nm or more to less than 490 nm.
4. A light emitting device comprising the light source device according to claim 1 .
5. A light source device comprising: at least one light emitting element of at least one type; at least one far-red phosphor that, when excited by output light from the at least one light emitting element, emits light having a peak in a wavelength range of 680 nm or more to less than 780 nm; at least one green phosphor; and at least one red phosphor,
wherein the spectrum of light emitted from the light source device has the following characteristic A:
characteristic A: the ratio of a minimum emission intensity to a maximum emission intensity in a wavelength range of from 400 nm to 750 nm inclusive is 20% or more.
6. The light source device according to claim 5 , wherein the at least one light emitting element has at least an emission peak in a wavelength range of 380 nm or more to less than 420 nm, and wherein the tight source device further comprises at least one blue phosphor that is excited by the output light from the at least one light emitting element.