A wavelength conversion element is provided that has excellent thermal conductance and high luminous efficiency. The wavelength conversion element includes: a binder; a plurality of phosphor particles dispersed in the binder, the plurality of phosphor particles being configured to emit light with a prescribed wavelength under excitation light; and a plurality of voids dispersed in the binder, at least some of the plurality of voids including, on at least a part of an inner wall thereof, a first coating film formed from metal alkoxide.

Provided is a fluorescent material with high brightness. The fluorescent material includes a nitride fluorescent material comprising La, Ce, Si, and N; and a first phosphorus compound disposed on a surface of the nitride fluorescent material. The first phosphorus compound includes at least one selected from the group consisting of lanthanum phosphate, lanthanum hydrogen phosphate, and hydrates thereof. A content of phosphorus atoms in the fluorescent material is 0.07% by mass or higher and 0.8% by mass or lower.

The laser projection apparatus includes a laser source, an optical engine and a projection lens. The laser source includes a base plate, a plurality of light-emitting components and a reflecting portion. The plurality of light-emitting components include a first light-emitting component and a second light-emitting component. The polarization direction of the laser beam emitted by one of the first light-emitting component and the second light-emitting component is parallel to the base plate, and the polarization direction of the laser beam emitted by another of the first light-emitting component and the second light-emitting component is perpendicular to the base plate. The reflecting prism is configured to change a polarization polarity of one of the laser beam with the polarization direction perpendicular to the base plate or the laser beam with the polarization direction parallel to the base plate.

A projection apparatus includes a casing, a projection lens, a first and a second light source modules, a first and a second thermal modules respectively thermally coupled to the first and the second light source modules, and a first and a second fans. The casing includes a bottom cover having a first air inlet corresponding to the projection lens, a front cover, a rear cover having a second air inlet, a first and a second side covers, which define an internal space divided into a first and a second areas. The first air inlet is connected to the internal space. A first air outlet of the first side cover and the second air inlet are connected to the first area. The first and the second light source modules, the first and the second thermal modules, and the first and the second fans are disposed in the first area.

A cooling device, a light-source device, an image projection apparatus, and a wavelength converter. The cooling device includes a housing having a storage space, the storage space storing a heater and a base on which the heater is disposed, a heatsink at least partially disposed in the storage space and thermally connected to a space outside the storage space to dissipate heat generated by the heater to outside of the storage space, and an airflow path forming member covering at least some of the heatsink and forming a path for the heatsink to receive air flow absorbing the heat generated by the heater. In the cooling device, the heater or the base at least partially protruding from the airflow path member when the airflow path member is viewed in a direction orthogonal to a face of the heater on which light strikes.

A light source apparatus according to an aspect of the present disclosure includes a light emitter that outputs light, a light guiding member that guides the light outputted from the light emitter, and a support member that supports the light guiding member. The light guiding member has a first surface and a second surface that intersect with the longitudinal direction of the light guiding member and are located on sides opposite from each other, and a third surface that intersects with the first and second surfaces, and causes light to exit via the first surface. The support member has a support surface that faces the third surface of the light guiding member. The support surface has a contact section that is in contact with the third surface and a noncontact section that is not in contact with the third surface. The third surface is a planar surface, and the contact section is a planar surface.

A light source apparatus according to an aspect of the present disclosure includes a circuit substrate that has a first surface and a second surface provided at the side opposite from the first surface and has a first opening passing through the first and second surfaces, a first light emitter that is electrically coupled to the circuit substrate and emits first light having a first wavelength band, and a thermal diffuser provided at the second surface of the circuit substrate, and the first light emitter is provided at the thermal diffuser exposed in the first opening.

A first cooling apparatus includes a first heat sink having multiple first fins having a U-shaped opening and an O-shaped opening which are provide therein, a first heat receiving member configured to be brought into abutment with a heat source, and a first heat pipe which extends from one end which is connected with the heat receiving member towards the other end, and the first heat pipe has a first extending portion which extends from the one end, a bent portion which is bent from the first extending portion and at least a part of which is disposed inside the U-shaped opening, and a second extending portion which extends from the bent portion and at least a part of which is disposed inside the O-shaped opening.

A first cooling apparatus includes a first heat sink having multiple first fins having a U-shaped opening and an O-shaped opening which are provide therein, a first heat receiving member configured to be brought into abutment with a heat source, and a first heat pipe which extends from one end which is connected with the heat receiving member towards the other end, and the first heat pipe has a first extending portion which extends from the one end, a bent portion which is bent from the first extending portion and at least a part of which is disposed inside the U-shaped opening, and a second extending portion which extends from the bent portion and at least a part of which is disposed inside the O-shaped opening.

The light source device includes a light source emitting a first light, a wavelength conversion element emitting a second light with a different wavelength from the first light by an incidence of the first light, a first optical system guiding the first light from the light source to the wavelength conversion element and including a reflecting element which reflects the first light with condensing it, and a second optical system exerting an optical action on the second light from the wavelength conversion element. The light source device satisfies the following conditional expression:

3≤α≤30

where α [degrees] represents an angle between an optical axis of the second optical system and a straight line passing through an intersection point between the optical axis of the second optical system and an exit surface of the wavelength conversion element, and a focal point of the reflecting element.