A light source device includes a light emitting element, and a microlens array having a first multi-lens surface and a second multi-lens surface. The light which enters the first multi-lens surface has an angular distribution. The first multi-lens surface has a plurality of first cells arranged in an array, and the second multi-lens surface has a plurality of second cells arranged in an array. Light proceeding from one of the first cells toward the second multi-lens surface has a first light beam which enters one second cell, and a second light beam which enters another second cell different from the one second cell. A first area of an illumination target is irradiated with the first light beam, and a second area of the illumination target different from the first area is irradiated with the second light beam.

The disclosure provides a display unit and a projection device. The display unit includes a first display panel having first light emitting elements configured to provide a first color light, a wavelength conversion element located on a transmission path of the first color light and having a conversion region and a non-conversion region, a second display panel having second light emitting elements configured to provide a second color light, and a light combining element. A quantum dot conversion material is disposed on the conversion region. Part of the first color light is converted into a third color light after passing through the conversion region, and another part of the first color light passes through the non-conversion region. The light combining element is located on transmission paths of the first color light, the second color light and the third color light and is configured to form an image beam.

The application relates to the technical field of projection, and discloses a projection device which can improve the brightness of projection imaging. Part of the projection device comprises: an LED light source, a color wheel, a light-equalizing rod, a convex lens, a first Fresnel lens, an LCD panel and a projection lens; a ray of target light emitted by the LED light source emits a target alternating light through the color wheel, and the target alternating light comprises five monochromatic lights including red light, green light, blue light, yellow light and white light, and the five monochromatic lights enter the light-equalizing rod for uniform treatment to emit an uniform light spot, the uniform light spot is imaged at the first Fresnel lens through the convex lens, then irradiated into the LCD panel, and projected by the projection lens.

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.

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.

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.

An illumination system and a projection apparatus are provided. The illumination system includes an excitation light source, a light guiding element, a filter module, an optical wavelength conversion module, and a homogenizing element. The light guiding element reflects an excitation beam coming from the excitation light source. The filter module includes a filtering region and receives the excitation beam reflected by the light guiding element. The optical wavelength conversion module includes a wavelength conversion region, receives the excitation beam reflected by the filtering region and reflects a conversion beam converted from the excitation beam. The conversion beam forms at least one color beam after passing through the filtering region of the filter module. The homogenizing element receives the excitation beam coming from the filter module and the at least one color beam. An incident angle of the excitation beam on the light guiding element is θ1, and θ1>0°.

A wavelength conversion module includes a ceramic substrate, a wavelength conversion layer, and a plurality of colloidal bosses. The ceramic substrate has a first surface. The wavelength conversion layer is disposed on the first surface of the ceramic substrate. The colloidal bosses are separately from each other disposed on the ceramic substrate and at least located on the first surface. The colloidal bosses and the wavelength conversion layer are separated from each other, and a heat resistant temperature of the colloidal bosses is higher than 500 degrees. The above wavelength conversion module has favorable heat dissipation effect.

A wavelength conversion module, including a first substrate, a second substrate, a counterweight ring, a first wavelength conversion layer, and a second wavelength conversion layer, is provided. The first substrate has a first upper surface. The second substrate has a second upper surface. The counterweight ring is disposed on the first upper surface of the first substrate and the second upper surface of the second substrate to connect the first substrate to the second substrate. The first wavelength conversion layer is disposed on the first upper surface of the first substrate and located around the counterweight ring. The second wavelength conversion layer is disposed on the second upper surface of the second substrate and located around the counterweight ring. A wavelength of a first excited beam emitted by the first wavelength conversion layer is greater than a wavelength of a second excited beam emitted by the second wavelength conversion layer.