A wavelength conversion structure and a projection device are provided. The wavelength conversion structure is disposed on a transmission path of an illumination light beam emitted by a light source of the projection device, and includes a rotary disc, a wavelength conversion material, and a scattering-reflective material. The rotary disc has a light-conversion region and a non-light-conversion region. The light-conversion region surrounds the non-light-conversion region. The wavelength conversion material is disposed on the rotary disc, and is aligned to the light-conversion region. An energy gap of the wavelength conversion material is smaller than photon energy of the illumination light beam. The scattering-reflective material is disposed on the rotary disc, and is aligned to the light-conversion region and not aligned to the non-light-conversion region. An energy gap of the scattering-reflective material is larger than the photon energy of the illumination light beam.

An immersive display system is disclosed that includes screens configured to mitigate reduction in contrast ratio due at least in part to peripheral light incident on the screens. The immersive display system includes at least two screens and at least two projector systems. The screens have a multi-layered structure configured to selectively reflect light in narrow wavelength bands. Each screen is configured to strongly diffusely reflect light in narrow wavelength bands that are different from the wavelength bands reflected by other screens in the immersive display system. Projector systems can be configured to provide light to associated screens in the narrow wavelength bands reflected by those screens.

An optical device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. In some examples, individual ones of the first and second segments can comprise specular reflecting, transparent, diffusely reflecting, and/or diffusely transmissive features. In some examples, individual ones of the first and second segments can comprise transparent and non-transparent regions. Some examples can incorporate more than one region producing an optical effect.

A projection module, time-divisionally projecting a first image light and a second image light, a beam splitter, reflecting the first image light and allowing the second image light to pass through, a reflector module comprising two reflectors symmetrically at opposite ends of the beam splitter reflecting the first image light and the second image light individually, then projecting the first image light and the second image light to a reflective diffuser, the reflective diffuser projecting the first image light and the second image light to a receiving area of a first eye and a second eye. The optical paths are symmetrical between the beam splitter and the reflective diffuser, thereby maintaining the same optical paths length of the first eye and the second eye, the image on the reflective diffuser being clear, projecting a clear stereoscopic image in a longer virtual image distance or in a greater image magnification application.

A wavelength conversion device, a manufacturing method thereof, and a related illumination device. The wavelength conversion device comprises a fluorescent powder layer (110) that is successively stacked, a diffuse reflection layer (120), and a high-thermal-conductivity substrate (130). The diffuse reflection layer (120) comprises white scattered particles for scattering the incident light; the high-thermal-conductivity substrate (130) is one of an aluminum nitride substrate, a silicon nitride substrate, a silicon carbide substrate, a boron nitride substrate, and a beryllium oxide substrate. The wavelength conversion device has good reflectivity and thermal stability.

A process for producing a transparent layered element exhibiting a diffuse reflection property, to this layered element as such and to the use thereof in a plurality of industrial applications. There is also provided a projection or back-projection method implementing such a layered element.

A diffusion member includes a first layer and a second layer, in this order, wherein the first layer has a light transmissivity and a light diffusivity, in the second layer, a reflectance of light increases as an absolute value of an incident angle with respect to a first layer side surface of the second layer decreases, and a transmittance of light increases as an absolute value of an incident angle with respect to a first layer side surface of the second layer increases.

A light harvester or collector collects solar radiation from an unshaded location adjacent a growing plant. The light harvester can be either imaging (e.g., parabolic reflectors) or non-imaging (e.g., compound parabolic concentrator). The concentrated solar radiation is projected into a light transmitter that conducts the light through the plant's outer canopy and into the inner canopy to a diffuser which disperses and reradiates the light into the inner canopy. The diffused light transforms a non-productive, potentially leafless zone of the plant into a productive zone so that more fruit can be produced per volume of land surface. The system can prevent transmission of infrared into the inner canopy so that the inner canopy zone is not heated and the amount of water lost to transpiration is reduced. The system can also modify other spectral components to affect plant development and to control pests and diseases.

The invention provides a system and related equipment for the precise measurement of the output characteristic of a light source, e.g., a dental light curing unit (LCU) or light for photodynamic therapy, using a light collector, a light detector, and a computer programmed to deliver the value of the output characteristic of the light source to the user. The systems allow for the determination of a proper 5 exposure time or the selection of a light source as needed for a specific application. The invention also provides a light device.

The present invention relates to a visibility improving film for a display panel and a display device including the same. More specifically, the present invention relates to a visibility improving film for a display panel capable of enhancing the visibility of a laser pointer and exhibiting excellent physical and optical properties, particularly preventing a specular reflection phenomenon of a laser pointer light, by including fine metal particles and inorganic oxide fine particles dispersed in a photocurable resin layer.