A cooling device of a projection display apparatus includes a first heat receiving unit including an opening that is rectangular. The first heat receiving unit includes a flow path part that forms the opening. An image display element of the projection display apparatus includes a first front face located in front of a reflective image display, a second front face parallel to the first front face and located behind and outside the first front face, and a first side face located between the first front face and the second front face. The first front face is inserted into the opening, and the flow path part is in contact with the first side face and the second front face via a heat conductive member. The flow path part includes a front face that is flush with or in front of the first front face of the image display element.

A light conversion device is disclosed. The light conversion device includes a substrate and a wavelength conversion element (111). The wavelength conversion element (111) includes an inorganic binder, such as sodium silicate. Also disclosed are phosphor wheels and light engines including such phosphor wheels. Further disclosed are high-power laser projection display systems comprising a laser having a power of from about 60 W and about 300 W and a light conversion device. The use of an inorganic binder permits high thermal stability at reasonable cost.

The present disclosure presents infant soothing devices which provide timed, color, and intensity controlled light and sound projections to assist in sleep therapy. The devices may be part of a smart nursery which has a number of electronically connected devices which communicate with a central electronic application to gather information and provide operation instructions to the devices. The smart nursery may be connected to a larger network to provide feedback and controllability outside of the nursery.

The present disclosure relates to a filter unit, a filter selection method, and an imaging device that allow continuously changing a transmittance of an ND filter and switching between filters to be performed more easily. A disk provided with a plurality of filters including an ND filter having a continuously variable transmittance is rotated to cause a filter corresponding to a rotational orientation of the disk among the plurality of filters provided on the disk to be arranged on an optical axis of incident light toward an image sensor. The present disclosure can be applied to, for example, a filter unit, an imaging device, electronic equipment, a filter selection method, a program, or the like.

An optical device is provided including a light-imaging component configured to focus light fed to the light-imaging component in at least one focusing spot, wherein the light fed includes at least one predefinable wavelength; and a conversion apparatus including at least one phosphor which is designed to convert light having the at least one predefinable wavelength into conversion light, wherein the conversion apparatus is arranged in such a way that the at least one phosphor is arranged in the focusing spot of the light-imaging component. The light-imaging component is configured to generate at least two focusing spots, and the conversion apparatus is arranged in such a way that the at least two focusing spots are positioned on the at least one phosphor.

Provided is a wavelength conversion member including a ceramic layer as a reflective layer and having excellent luminescence intensity and a light emitting device using the same. A wavelength conversion member 10 including: a first porous ceramic layer 1 having a porosity of 20% by volume or more; and a phosphor layer 2 formed on a principal surface 1a of the first porous ceramic layer 1.

A wavelength conversion module and a projector including the wavelength conversion module are provided. The wavelength conversion module includes a substrate and a wavelength conversion layer. The substrate has a first surface and a second surface opposite to each other. The substrate includes a plurality of turbulent portions, and the turbulent portions are recessed in at least one of the first surface and the second surface. The wavelength conversion layer is disposed on the first surface of the substrate, and a distribution area of the turbulent portions accounts for more than 60% of an exposure area of the substrate. The wavelength conversion module and the projector provided by the disclosure exhibit favorable heat dissipation efficiency.

An illumination system and a projection device are provided. The illumination system includes a laser light source, a light splitting element, a wavelength conversion module, a filter module, and a homogenizing element. The laser light source provides a laser beam to the light splitting element. The filter module rotates around a rotation axis and has multiple dichroic filter regions on a surface perpendicular to the rotation axis. The filter module receives the laser beam from the light splitting element, and an acute angle is formed between the rotation axis and a direction in which the laser beam enters the filter module. The homogenizing element is located on a transmission path of the laser beam penetrating the filter module, and the laser beam enters the homogenizing element along a long axis direction of the homogenizing element.

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.