Light source device
A light source device having: a blue light emitting element that emits blue light having an emission peak in a wavelength region of 440 nm to 460 nm; a green phosphor that absorbs part of the blue light emitted by the blue light emitting element and thereby emits green light having an emission peak in a wavelength region of 500 nm to 575 nm; a red phosphor that absorbs at least one of part of the blue light emitted by the blue light emitting element and part of the green light emitted by the green phosphor, and thereby emits red light having an emission peak in a wavelength region of 600 nm to 690 nm; and an absorbent containing neodymium fluoride that absorbs part of the green light and part of the red light.
1. A light source device comprising:
(i) a blue light emitting element that emits blue light having an emission peak in a wavelength region of 440 nm to 460 nm; and
(ii) a light-transmissive member that encapsulates the blue light emitting element and contains:
(a) a green phosphor that absorbs part of the blue light emitted by the blue light emitting element and thereby emits green light having an emission peak in a wavelength region of 500 nm to 575 nm;
(b) a red phosphor that absorbs at least one of part of the blue light emitted by the blue light emitting element and part of the green light emitted by the green phosphor, and thereby emits red light having an emission peak in a wavelength region of 600 nm to 690 nm; and
(c) an absorbent containing neodymium fluoride that absorbs part of the green light and part of the red light,
wherein the content ratio of the absorbent is 0.1 mass % to 15.0 mass % with respect to a total mass of the light-transmissive member.
2. A light source device as set forth in claim 1 ,
wherein the absorbent is composed of a crystalline compound.
3. A light source device as set forth in claim 1 ,
wherein the green phosphor contains at least one selected from the group consisting of a sulfide phosphor, an oxinitride phosphor, and an oxide phosphor.
4. A light source device as set forth in claim 1 ,
wherein the red phosphor contains at least one selected from the group consisting of a fluoride phosphor, a nitride phosphor, an oxinitride phosphor, and a sulfide phosphor.
5. A light source device as set forth in claim 1 ,
wherein the green phosphor has an emission peak in a wavelength region of 520 nm to 550 nm.
6. A light source device as set forth in claim 1 ,
wherein the red phosphor has an emission peak in a wavelength region of 620 nm to 670 nm.
7. A light source device as set forth in claim 1 ,
wherein the absorbent contains a composition having the formula: Nd 1-x R x F 3 , wherein R is a rare earth element other than Nd, and wherein 0≤x<1.
8. A light source device as set forth in claim 1 ,
wherein, when an emission intensity at an emission peak of the blue light emitting element is taken as 1, an emission intensity at an emission peak of the green phosphor is 0.15 to 0.5 and an emission intensity at an emission peak of the red phosphor is 0.1 to 2.5.
9. A light source device, comprising:
(i) a blue light emitting element that emits blue light having an emission peak in a wavelength region of 440 nm to 460 nm;
(ii) a first light-transmissive member that encapsulates the blue light emitting element and contains:
(a) a green phosphor that absorbs part of the blue light emitted by the blue light emitting element and thereby emits green light having an emission peak in a wavelength region of 500 nm to 575 nm; and
(b) a red phosphor that absorbs at least one of part of the blue light emitted by the blue light emitting element and part of the green light emitted by the green phosphor, and thereby emits red light having an emission peak in a wavelength region of 600 nm to 690 nm; and
(iii) a second light-transmissive member that covers the first light-transmissive member and contains an absorbent containing neodymium fluoride that absorbs part of the green light and part of the red light.
10. A light source device as set forth in claim 9 ,
wherein the content ratio of the absorbent is 0.1 mass % to 15.0 mass % with respect to a total mass of the second light-transmissive member.
11. A light source device as set forth in claim 9 ,
wherein, when an emission intensity at an emission peak of the blue light emitting element is taken as 1, an emission intensity at an emission peak of the green phosphor is 0.15 to 0.5 and an emission intensity at an emission peak of the red phosphor is 0.1 to 2.5.
12. A light source device, comprising:
(i) a blue light emitting element that emits blue light having an emission peak in a wavelength region of 440 nm to 460 nm;
(ii) a green phosphor that absorbs part of the blue light emitted by the blue light emitting element and thereby emits green light having an emission peak in a wavelength region of 500 nm to 575 nm;
(iii) a red phosphor that absorbs at least one of part of the blue light emitted by the blue light emitting element and part of the green light emitted by the green phosphor, and thereby emits red light having an emission peak in a wavelength region of 600 nm to 690 nm; and
(iv) a light diffusion plate containing an absorbent containing neodymium fluoride that absorbs part of the green light and part of the red light and having: (a) a first principal surface into which a mixture of the blue light, the green light, and the red light enters; and (b) a second principal surface from which the mixture of the blue light, the green light, and the red light emerges.
13. A light source device as set forth in claim 12 ,
wherein the content ratio of the absorbent is 0.1 mass % to 15.0 mass % with respect to a total mass of the light diffusion plate.
14. A light source device as set forth in claim 12 ,
wherein, when an emission intensity at an emission peak of the blue light emitting element is taken as 1, an emission intensity at an emission peak of the green phosphor is 0.15 to 0.5 and an emission intensity at an emission peak of the red phosphor is 0.1 to 2.5.
15. A light source device, comprising:
(i) a blue light emitting element that emits blue light having an emission peak in a wavelength region of 440 nm to 460 nm;
(ii) a green phosphor that absorbs part of the blue light emitted by the blue light emitting element and thereby emits green light having an emission peak in a wavelength region of 500 nm to 575 nm;
(iii) a red phosphor that absorbs at least one of part of the blue light emitted by the blue light emitting element and part of the green light emitted by the green phosphor, and thereby emits red light having an emission peak in a wavelength region of 600 nm to 690 nm; and
(iv) a light guide plate containing an absorbent containing neodymium fluoride that absorbs part of the green light and part of the red light and having: (a) a side surface into which a mixture of the blue light, the green light, and the red light enters; and (b) at least one principal surface from which the mixture of the blue light, the green light, and the red light emerges.
16. A light source device as set forth in claim 15 ,
wherein the content ratio of the absorbent is 0.1 mass % to 15.0 mass % with respect to a total mass of the light guide plate.
17. A light source device as set forth in claim 15 ,
wherein, when an emission intensity at an emission peak of the blue light emitting element is taken as 1, an emission intensity at an emission peak of the green phosphor is 0.15 to 0.5 and an emission intensity at an emission peak of the red phosphor is 0.1 to 2.5.