Lighting device and projection display apparatus
View Patent ↗A lighting device of the present disclosure includes an excitation light source, a phosphor, a spreader, a reflective layer, and a reflective region. The excitation light source emits a polarized light. The phosphor receives the light as an excitation light from the excitation light source, and emits a fluorescent light, the phosphor including a plurality of phosphor pieces adjacently disposed on the reflective layer, the plurality of phosphor pieces having a same characteristic. The spreader supports the phosphor. The reflective layer is disposed between the phosphor and the spreader, and reflects the fluorescent light. The reflective region is disposed between the plurality of phosphor pieces, the reflective region reflecting the received excitation light while keeping a polarization characteristic of the received excitation light.
1. A lighting device comprising:
an excitation light source configured to emit a polarized light;
a phosphor configured to receive the polarized light as an excitation light from the excitation light source, and emit a fluorescent light, the phosphor including a plurality of phosphor pieces configured to emit the fluorescent light having a same wavelength;
a spreader configured to support the phosphor;
a reflective layer disposed between the phosphor and the spreader, and configured to reflect the fluorescent light, wherein the plurality of phosphor pieces are adjacently disposed on the reflective layer; and
a reflective region disposed between the plurality of phosphor pieces, the reflective region reflecting the received excitation light while keeping a polarization characteristic of the received excitation light, wherein
the reflective region includes:
a light-transmitting member; and
a reflective portion disposed between the light-transmitting member and the spreader.
2. The lighting device according to claim 1 , wherein a reflective surface of the reflective region configured to receive the excitation light has an uneven shape.
3. A lighting device comprising:
an excitation light source configured to emit a polarized light;
a phosphor configured to receive the polarized light as an excitation light from the excitation light source, and emit a fluorescent light, the phosphor including a plurality of phosphor pieces configured to emit the fluorescent light having a same wavelength;
a spreader configured to support the phosphor;
a reflective layer disposed between the phosphor and the spreader, and configured to reflect the fluorescent light, wherein the plurality of phosphor pieces are adjacently disposed on the reflective layer; and
a reflective region disposed between the plurality of phosphor pieces, the reflective region reflecting the received excitation light while keeping a polarization characteristic of the received excitation light,
wherein a reflective surface of the reflective region configured to receive the excitation light has a fine uneven portion on a projecting or recessed reference surface.
4. A lighting device comprising:
an excitation light source configured to emit a polarized light;
a phosphor configured to receive the polarized light as an excitation light from the excitation light source, and emit a fluorescent light, the phosphor including a plurality of phosphor pieces configured to emit the fluorescent light having a same wavelength;
a spreader configured to support the phosphor;
a reflective layer disposed between the phosphor and the spreader, and configured to reflect the fluorescent light, wherein the plurality of phosphor pieces are adjacently disposed on the reflective layer; and
a reflective region disposed between the plurality of phosphor pieces, the reflective region reflecting the received excitation light while keeping a polarization characteristic of the received excitation light,
wherein
the reflective region includes a reflective surface configured to receive the excitation light,
the plurality of phosphor pieces include phosphor surfaces configured to receive the excitation light, and
an area ratio of the reflective surface to the phosphor surfaces is 10-20 to 100.
5. The lighting device according to claim 1 , wherein
the reflective region includes a reflective surface configured to receive the excitation light,
the plurality of phosphor pieces include phosphor surfaces configured to receive the excitation light, and
when an area change rate of an effective range of the excitation light received by the phosphor is 20% or less, a change rate of an area ratio of the reflective surface to the phosphor surfaces in the effective range is a half or less of the area change rate.
6. The lighting device according to claim 1 , wherein the reflective region is in direct contact with the spreader, the reflective layer, and the plurality of phosphor pieces.
7. The lighting device according to claim 1 , wherein a surface roughness of the reflective region is larger than a surface roughness of the plurality of phosphor pieces.
8. The lighting device according to claim 1 , wherein a surface of the reflective region protrudes with respect to a surface of the phosphor.
9. The lighting device according to claim 1 , wherein
the reflective layer includes a plurality of reflective portions, and
the reflective region is between the plurality of reflective portions.
10. The lighting device according to claim 9 , wherein the reflective region is in direct contact with the plurality of reflective portions.
11. The lighting device according to claim 3 , wherein a reflective surface of the reflective region configured to receive the excitation light has an uneven shape.
12. The lighting device according to claim 3 , wherein
the reflective region includes a reflective surface configured to receive the excitation light,
the plurality of phosphor pieces include phosphor surfaces configured to receive the excitation light, and
when an area change rate of an effective range of the excitation light received by the phosphor is 20% or less, a change rate of an area ratio of the reflective surface to the phosphor surfaces in the effective range is a half or less of the area change rate.
13. The lighting device according to claim 3 , wherein the reflective region is in direct contact with the spreader, the reflective layer, and the plurality of phosphor pieces.
14. The lighting device according to claim 3 , wherein a surface roughness of the reflective region is larger than a surface roughness of the plurality of phosphor pieces.
15. The lighting device according to claim 3 , wherein a surface of the reflective region protrudes with respect to a surface of the phosphor.
16. The lighting device according to claim 3 , wherein
the reflective layer includes a plurality of reflective portions, and
the reflective region is between the plurality of reflective portions.
17. The lighting device according to claim 16 , wherein the reflective region is in direct contact with the plurality of reflective portions.