Illumination apparatus, color conversion device, and display apparatus

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.

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.

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.