A light source device of the present disclosure includes a sapphire plate having a first surface and a second surface facing each other, a wavelength conversion material located opposite the first surface of the sapphire plate, and a first excitation light source emitting a first excitation light having directivity to the wavelength conversion material through the second surface, in which an angle between the first surface and the second surface, and a c-axis of sapphire is greater than 80°, and an angle between the c-axis and an optical axis of the first excitation light is 20° or more. A lighting device of the present disclosure includes the light source device and a light guide member.

A light source device, includes: a plurality of excitation light sources that emit primary light; an optical member that condenses the primary light; a fluorescent unit that emits secondary light including the primary light and wavelength converted light which is at least some of the primary light on which wavelength conversion is performed; and a sensor that detects an anomaly in the fluorescent unit. In addition, when seen along an optical axis of the primary light emitted by the plurality of excitation light sources, the sensor circumscribes, among the plurality of excitation light sources, a first excitation light source and a second excitation light source different from the first excitation light source, and is disposed inside an imaginary circle having, as a diameter, a line segment connecting the first excitation light source and the second excitation light source.

A photoconversion device includes a holder, a wavelength converter, and an optical element. The holder holds an output portion that outputs excitation light. The wavelength converter includes an incident surface section including a protruding surface to receive the excitation light from the output portion and emits fluorescence in response to the excitation light incident on the incident surface section. The optical element includes a focal point surrounded by the incident surface to direct the fluorescence emitted by the wavelength converter in a predetermined direction.

A photoconversion device includes a holder, a wavelength converter, and an optical element. The holder holds an output portion that outputs excitation light. The wavelength converter includes an incident surface section including a protruding surface to receive the excitation light from the output portion and emits fluorescence in response to the excitation light incident on the incident surface section. The optical element includes a focal point surrounded by the incident surface to direct the fluorescence emitted by the wavelength converter in a predetermined direction.

A lighting device disclosed in the embodiment of the invention includes a base member including a straight portion and a curved portion, a substrate including a first substrate disposed on the straight portion of the base member and a second substrate disposed on the curved portion; a plurality of light sources disposed on each of the first and second substrates, a resin layer including a first resin portion disposed on the first substrate and a second resin portion surrounding the second substrate, and a phosphor layer disposed on the resin layer, and an outer side surface of the second resin portion may include a curved surface.

The invention describes a light converting device comprising: a bonded layer stack comprising a light converter and a diamond layer, wherein the diamond layer is bonded to a bonding surface of the light converter, wherein the light converter is adapted to convert laser light to converted light, wherein a peak emission wavelength of the converted light is in a longer wavelength range than a laser peak emission wavelength of the laser light, wherein a refractive index of the diamond layer is bigger than a refractive index of the light converter, and a light outcoupling structure attached to a first surface of the bonded layer stack, wherein a second surface of the bonded layer stack is a light-entrance surface arranged to receive the laser light, wherein the bonding surface is arranged between the first surface and the second surface of the bonded layer stack, wherein a refractive index of the light outcoupling structure is at least 90% of the refractive index of the light converter, and wherein the light outcoupling structure is optically coupled to the first surface of the bonded layer stack such that total internal reflection of light traversing an emission path from the light-entrance surface to the light outcoupling structure is reduced. The invention further describes a laser-based light source comprising such a light converting device and a vehicle headlight comprising such a laser-based light source.

An image display apparatus according to an embodiment of the present technology includes a base, a light emission body, a dichroic film, and a heat conduction member. The light emission body is provided on the base, and emits visible light by being excited by excitation light. The dichroic film reflects at least a part of the visible light emitted from the light emission body. The heat conduction member is provided on the base, and diffuses heat transmitted from the light emission body to the base.

Embodiments of the disclosure are related to a backlight unit and a display device, by disposing a filter reflecting a green light of a long wavelength on a color conversion sheet and disposing a filter reflecting a green light and a red light under the color conversion sheet, a wavelength band of a light supplied to a display panel is controlled and a color reproduction range may be improved while increasing a light efficiency. Furthermore, by disposing a sheet increasing an amount of a vertical light on the color conversion sheet, a wavelength band of a light reflected by a filter disposed on the color conversion sheet is controlled exactly and the backlight unit and the display device capable of a wide color gamut may be provided.

[Object] Collection efficiency of a reflector that reflects a converted beam, which is converted from a pump beam by a phosphor, and projects the resultant as a projection beam is increased. [Solution] An optical member (4) of a light source unit (1) deflects a pump beam (PB) so that a first angle of incidence (1) of a pump beam (PBX) relative to a surface of a phosphor (3) is larger than a second angle of incidence (2) of the pump beam (PB), which is incident on the optical member (4), relative to the surface of the phosphor (3).

[Object] Collection efficiency of a reflector that reflects a converted beam, which is converted from a pump beam by a phosphor, and projects the resultant as a projection beam is increased. [Solution] An optical member (4) of a light source unit (1) deflects a pump beam (PB) so that a first angle of incidence (1) of a pump beam (PBX) relative to a surface of a phosphor (3) is larger than a second angle of incidence (2) of the pump beam (PB), which is incident on the optical member (4), relative to the surface of the phosphor (3).