Illumination apparatus, color conversion device, and display apparatus
An illumination apparatus includes a transparent substrate, a phosphor layer, an optical wavelength selection filter layer, and a light-emitting device. The transparent substrate includes a first surface and a second surface opposing each other. The phosphor layer is disposed on the first surface side of the transparent substrate. The optical wavelength selection filter layer is disposed on the second surface side of the transparent substrate and configured to transmit light of a first wavelength therethrough and reflect light of a second wavelength that is emitted from the phosphor layer by being excited by the light of the first wavelength. The light-emitting device is configured to emit the light of the first wavelength from the optical wavelength selection filter layer side thereof toward the optical wavelength selection filter layer.
1. An illumination apparatus, comprising:
a transparent substrate including oppositely facing first and second surfaces;
a phosphor layer disposed on a first surface side of the transparent substrate;
an optical wavelength selection filter layer disposed on a second surface side of the transparent substrate and configured to transmit light of a first wavelength therethrough and reflect light of a second wavelength that is emitted from the phosphor layer by being excited by the light of the first wavelength; and
a light-emitting device configured to emit the light of the first wavelength toward the optical wavelength selection filter layer,
wherein,
the optical wavelength selection filter layer is between the transparent substrate and the light-emitting device,
the optical wavelength selection filter layer includes at least a first film and a second film, and
the first film is in contact with the second surface of the transparent substrate, the first film having a greater refractive index than the second film.
2. The illumination apparatus according to claim 1 ,
wherein the light-emitting device is a blue-light-emitting diode, and
wherein the phosphor layer includes a phosphor that emits green light by being excited by excitation light that is blue light and a phosphor that emits red light by being excited by the excitation light.
3. The illumination apparatus according to claim 1 ,
wherein the light-emitting device is a blue-light-emitting diode, and
wherein the phosphor layer includes a phosphor that emits yellow light by being excited by excitation light that is blue light.
4. The illumination apparatus according to claim 1 ,
wherein the light-emitting device is a purple-light-emitting diode, and
wherein the phosphor layer includes a phosphor that emits red light by being excited by excitation light that is purple light, a phosphor that emits green light by being excited by the excitation light, and a phosphor that emits blue light by being excited by the excitation light.
5. The illumination apparatus according to claim 1 , wherein the optical wavelength selection filter layer is obtained by laminating at least the first film and the second film, the first film being an Nb 2 O 5 film and the second film being an SiO 2 film.
6. The illumination apparatus according to claim 1 , wherein a plurality of light-emitting devices are provided in correspondence with an entire surface of the transparent substrate.
7. The illumination apparatus according to claim 1 , further comprising a light guide plate disposed on an optical path of the light emitted from the light-emitting device, between the light-emitting device and the optical wavelength selection filter layer.
8. The illumination apparatus according to claim 7 , wherein a plurality of light-emitting devices are provided along an end portion of the light guide plate.
9. The illumination apparatus according to claim 1 , further comprising a protection film that has a moisture barrier function, the protection film disposed on a surface of the phosphor layer opposed to a surface thereof on the first surface side of the transparent substrate.
10. The illumination apparatus according to claim 1 , further comprising an antireflection layer disposed on a surface of the phosphor layer opposed to a surface thereof on the first surface side of the transparent substrate.
11. An illumination apparatus, comprising:
a light guide plate;
a plurality of light-emitting devices disposed along an end portion of the light guide plate and each configured to emit light of a first wavelength;
a phosphor layer;
a transparent substrate; and
an optical wavelength selection filter layer configured to transmit the light of the first wavelength therethrough and reflect light of a second wavelength that is emitted from the phosphor layer by being excited by the light of the first wavelength,
wherein,
the phosphor layer, the transparent substrate, and the optical wavelength selection filter layer are disposed between the light guide plate and the plurality of light-emitting devices in the stated order from the light guide plate side,
the optical wavelength selection filter layer includes at least a first film and a second film, and
the first film is in contact with the second surface of the transparent substrate, the first film having a greater refractive index than the second film.
12. A color conversion device, comprising:
a transparent substrate including oppositely facing first and second surfaces;
a phosphor layer disposed on a first surface side of the transparent substrate;
a light-emitting device; and
an optical wavelength selection filter layer disposed on a second surface side of the transparent substrate and configured to transmit light of a first wavelength therethrough and reflect light of a second wavelength,
wherein,
the optical wavelength selection filter layer is between the transparent substrate and the light-emitting device,
the optical wavelength selection filter layer includes at least a first film and a second film, and
the first film is in contact with the second surface of the transparent substrate, the first film having a greater refractive index than the second film.
13. A display apparatus, comprising:
a display panel; and
an illumination apparatus provided adjacent to the display panel, the illumination apparatus including
a transparent substrate including oppositely facing first and second surfaces,
a phosphor layer disposed on a first surface side of the transparent substrate,
an optical wavelength selection filter layer disposed on a second surface side of the transparent substrate and configured to transmit light of a first wavelength therethrough and reflect light of a second wavelength that is emitted from the phosphor layer by being excited by the light of the first wavelength, and
a light-emitting device configured to emit the light of the first wavelength toward the optical wavelength selection filter layer,
wherein,
the optical wavelength selection filter layer is between the transparent substrate and the light-emitting device,
the optical wavelength selection filter layer includes at least a first film and a second film, and
the first film is in contact with the second surface of the transparent substrate, the first film having a greater refractive index than the second film.