Phosphor wheel apparatus, lighting apparatus, and projection type image display apparatus

1. A phosphor wheel apparatus comprising:

a substrate made of aluminum alloy having a first light reflectance, the substrate having a first surface and a second surface facing opposite to each other;

a phosphor layer disposed on the first surface of the substrate;

an adhesive layer bonding the substrate and the phosphor layer to each other; and

a drive apparatus configured to rotate the substrate, the substrate having a circular shape, and the phosphor layer having a ring shape;

wherein the substrate has a plurality of integral fins extending from the second surface of the substrate such that the fins form a one-piece construction with the substrate,

wherein the adhesive layer includes an adhesive having a first thermal conductivity and filler particles,

wherein the filler particles have a second thermal conductivity higher than the first thermal conductivity, and have a second light reflectance higher than the first light reflectance,

wherein the fins are configured to each be in rotational symmetry with respect to a rotation center of the substrate, and an arbitrary radius of the substrate intersects with at least two fins,

wherein at a position corresponding to an outer periphery of the phosphor layer, when an angle viewing from the first surface to a width of one fin on the second surface is represented by θ 1 and an angle viewing from the first surface to a distance between two fins adjacent to each other on the second surface is represented by θ 2 , each of the fins is formed to satisfy:

θ 1 <55° and θ 2 <140°.

2. The phosphor wheel apparatus according to claim 1 , wherein the phosphor layer is made of a ceramic.

3. The phosphor wheel apparatus according to claim 1 , wherein the filler particles are made of titanium oxide.

4. The phosphor wheel apparatus according to claim 1 , further comprising a reflective layer formed between the substrate and the adhesive layer.

5. The phosphor wheel apparatus according to claim 1 , wherein the fins are configured to each be along a part of a spiral.

6. A lighting apparatus comprising:

a light source element; and

the phosphor wheel apparatus according to claim 1 .

7. A projection image display apparatus comprising:

the lighting apparatus according to claim 6 ;

a light modulation element configured to spatially modulate incident light from the lighting apparatus according to an image signal to generate image light; and

a projection optical system for projecting the image light.