Abstract: A head-mounted display including a transparent display, a first liquid crystal lens and a second liquid crystal lens is provided. The transparent display is adapted to emit an image light beam. The first liquid crystal lens is disposed beside the transparent display. The transparent display is disposed between the first liquid crystal lens and the second liquid crystal lens. The second liquid crystal lens is adapted to receive an ambient light beam. The image light beam passes through the first liquid crystal lens by the phase changing of the first liquid crystal lens, and then the image light beam passes through a pupil.

Abstract: A rear projection screen includes a transparent substrate, a light absorbing film and a first diffusion film in sequence from a projection side to a viewer side. The transparent substrate includes a first surface and a second surface opposite to each other, the first surface faces the projection side, the second surface faces the viewer side, and the first surface is disposed with a plurality of prism structures protruding toward the projection side. The transparent substrate is located between the light absorbing film and the prism structures. The light absorbing film incudes a plurality of light absorbing structures arranged at intervals from each other, and the distribution density of the prism structures is greater than that of the light absorbing structures. The light absorbing film is located between the first diffusion film and the transparent substrate. The rear projection screen through the above-mentioned design has a good image display quality.

Abstract: An optical waveguide element including a light entrance portion and a light exit portion is provided. The light entrance portion includes a first light guide layer, a second light guide layer, and at least one third light guide layer. Light entrance surfaces of the first light guide layer and the second light guide layer jointly compose a first inclined surface. Light exit surfaces of the first light guide layer and the second light guide layer jointly compose a second inclined surface. The first inclined surface and the second inclined surface are inclined relative to a bottom surface of the first light guide layer. The thickness of the light exit portion is less than the total thickness of the first light guide layer, the second light guide layer, and the at least one third light guide layer. A display device is also provided.

Abstract: A wavelength conversion device includes a substrate, a first glue substance, a wavelength conversion structure, and a second glue substance. The substrate includes a first surface, a second surface, and an axis. The first glue substance is disposed between the wavelength conversion structure and the first surface and surrounds the axis. The wavelength conversion structure is disposed on the first glue substance and surrounds the axis. The wavelength conversion structure includes a first bonding surface, a first lateral surface, and a second lateral surface. The first bonding surface faces to the first glue substance and is connected between the first lateral surface and the second lateral surface. The first lateral surface faces in the direction away from the axis, whereas the second lateral surface faces in the direction close to the axis. The second glue substance is connected to the first lateral surface and surrounds the axis.

Abstract: An illumination system includes a coherent light source, a first light-combining device, an optical wavelength conversion module, and a first auxiliary light source. The coherent light source emits a coherent light beam. The first light-combining device is disposed on a transmission path of the coherent light beam. The light wavelength conversion module is disposed on a transmission path of the coherent light beam transmitted from the first light-combining device and converts the coherent light beam into a first converted light beam, and reflects the first converted light beam back to the first light-combining device. The first auxiliary light source emits a first auxiliary light beam which is transmitted to the first light-combining device. The first light-combining device combines the first auxiliary light beam and the first converted light beam. A projection apparatus and a method for driving the illumination system are also provided.

Abstract: The invention provides a projection apparatus and an illumination system. The projection apparatus includes an illumination system, a light valve, and a projection lens. The illumination system includes at least one laser light source, at least one light separating element, a wavelength conversion element, and a reflective element. The at least one laser light source is adapted to generate at least one laser beam, and the at least one laser beam is adapted to penetrate at least one first coating region of the light separating element. The wavelength conversion element is adapted to convert the laser beam from the light separating element into a converted beam. A second coating region of a reflective surface of the reflective element is adapted to reflect a portion of the laser beam from the wavelength conversion element, and the second coating region and the first coating region are adapted to reflect the converted beam. The portion of the laser beam and the converted beam constitute an illumination beam.

Abstract: A projection screen, adapted to receive an image beam, includes a transparent substrate, optical pillar structures, a light-scattering layer, Fresnel structures and a light-absorption layer. The transparent substrate has first surface and second surface opposing to each other. The optical pillar structures are located at the first surface, and between the light-scattering layer and the transparent substrate. Each optical pillar structure is arranged along the first direction. The Fresnel structures are located at the second surface, and disposed between the transparent substrate and the light-absorption layer. Each Fresnel structure has a reflective surface and a transmissive surface connected to the reflective surface. The image beam sequentially passes through the light-scattering layer, the optical pillar structures, the transparent substrate and travels to the reflective surfaces, and the image beam is reflected by the reflective surfaces and outputs from the projection screen.

Abstract: An illumination system including a coherent light source device, a light delivery module, and a light wavelength conversion module is provided. The coherent light source device includes a light emitting source and a light collimating element. The light emitting source is adapted to emit at least one coherent light beam. The light collimating element is located on a transmission path of the at least one coherent light beam from the light emitting source and collimates the at least one coherent light beam. The light delivery module is located on a transmission path of at least one coherent light beam from the light collimating element and includes a first lens. The first lens has a lens array surface adapted to diverge any of the coherent light beam from the light collimating element. A projection apparatus is also provided.

Abstract: A light guide element of a wearable apparatus adapted to guide a light beam includes first and second light guide plates and a light splitting film. The first light guide plate has first and second surfaces, and a light entrance surface. The second light guide plate is disposed on the partial first surface and located on a transmission path of the light beam. The light splitting film is disposed between the partial first surface and the second light guide plate, and adjacent to the light entrance surface. The light splitting film is adapted to reflect a portion of the light beam and allow the partial light beam from the partial first surface to pass to the second light guide plate.

Abstract: An illumination system includes a coherent light source, a first light-combining element, an optical wavelength conversion module, and a first auxiliary light source. The coherent light source emits a coherent light beam. The first light-combining element is disposed on a transmission path of the coherent light beam. The light wavelength conversion module is disposed on a transmission path of the coherent light beam transmitted from the first light-combining element and converts the coherent light beam into a first converted light beam, and reflects the first converted light beam back to the first light-combining element. The first auxiliary light source emits a first auxiliary light beam which is transmitted to the first light-combining element along the transmission path of the coherent light beam. The first light-combining element combines the first auxiliary light beam and the first converted light beam. A projection apparatus is also provided.

Abstract: A head-mounted display including an apparatus body and an image display device is provided. The apparatus body includes a first part and a second part connected to the first part. The image display device is disposed at the apparatus body and adapted to project a display image to a projection target. The image display device includes a fiber element and an imaging element. The fiber element is adapted to transmit an illumination beam. The imaging element is adapted to project the image beam to the projection target to display the display image. The fiber element is disposed at the first part of the apparatus body. The imaging element is disposed at one of the first part and the second part of the apparatus body. The head-mounted display is capable of expanding the user's field of view and reducing the size and weight.

Abstract: A head-mounted display including an apparatus body including a first part and a second part connected to the first part and an image display device disposed in the apparatus body is provided. The image display device projects an image to a projection target and includes an image output element, a plurality of lens elements, a light diffuser, and an imaging element. The imaging element projects the image beam to the projection target to display the image. The lens elements include a first lens element and a second lens element. The image output element generates an intermediate image on a transmitting path of the image beam between the first and second lens elements. The light diffuser is disposed on the transmitting path of the image beam and in a predetermined interval where the intermediate image is located at the center.

Abstract: A head-mounted display including an apparatus body and an image display device is provided. The apparatus body includes a first part and a second part assembled to the first part. The image display device is disposed in the apparatus body, projects an image to a projection target, and includes an image output element, a plurality of lens elements, and an imaging element. The image output element outputs an image beam transmitted to the imaging element through the lens elements. The imaging element projects the image beam to the projection target to display the image. The image output element and the lens elements are disposed in the first part. The projection target is located on a reference plane, on which a projection of the image output element is above the projection target.

Abstract: An optical object positioning apparatus including an optical element, a light sensor and a processing unit and a positioning method thereof are provided. The optical element includes a first surface and a second surface opposite to each other and perpendicular to a first axis, and has at least two light-passing regions. Light beams from an object to be positioned pass through the light-passing regions from the first surface to the second surface. The light sensor and the optical element are spaced by a predetermined distance on a direction of the first axis. The light sensor senses the light beams from the light-passing regions to generate at least two light-sensing signals. A distance between the object and the optical element is positively correlated to the predetermined distance. The processing unit receives the light-sensing signals and positions the object according to the light-sensing signals and the predetermined distance.

Abstract: A wavelength conversion device including a main body and a transparent element is provided. The main body has at least one wavelength conversion region, a containing recess portion, and a stop portion. The containing recess portion and the stop portion encircle a closed slot. The transparent element is disposed in the closed slot to construct a light penetration region. The stop portion stops the transparent element along a radial direction of the main body. Moreover, a projector using the wavelength conversion device is also mentioned.

Abstract: A head-mounted display including a transparent display, a first liquid crystal lens and a second liquid crystal lens is provided. The transparent display is adapted to emit an image light beam. The first liquid crystal lens is disposed beside the transparent display. The transparent display is disposed between the first liquid crystal lens and the second liquid crystal lens. The second liquid crystal lens is adapted to receive an ambient light beam. The image light beam passes through the first liquid crystal lens by the phase changing of the first liquid crystal lens, and then the image light beam passes through a pupil.

Abstract: A head-mounted display including a transparent display, a liquid crystal lens and a first Fresnel lens is provided. The transparent display is configured to emit an image light beam. The liquid crystal lens is disposed near the transparent display. The transparent display is disposed between the liquid crystal lens and the first Fresnel lens. The first Fresnel lens is configured to receive an ambient light beam. The head-mounted display allows at least a part of the image light beam emitted from the transparent display passing through a pupil by phase modulating of at least a part of the liquid crystal lens.

Abstract: A head-mounted display apparatus including a main body, a mask, and a projection apparatus is provided. The mask is pivotally connected to the main body. The mask includes a reflection area. The reflection area has a first normal line. The projection apparatus is disposed inside the main body and adapted to project an image beam to a target. The projection apparatus includes a mirror. The mirror has a second normal line. An acute angle exists between normal projections of the first normal line and the second normal line on a reference plane.

Abstract: A projection screen, adapted to receive an image beam, includes a transparent substrate, optical pillar structures, a light-scattering layer, Fresnel structures and a light-absorption layer. The transparent substrate has first surface and second surface opposing to each other. The optical pillar structures are located at the first surface, and between the light-scattering layer and the transparent substrate. Each optical pillar structure is arranged along the first direction. The Fresnel structures are located at the second surface, and disposed between the transparent substrate and the light-absorption layer. Each Fresnel structure has a reflective surface and a transmissive surface connected to the reflective surface. The image beam sequentially passes through the light-scattering layer, the optical pillar structures, the transparent substrate and travels to the reflective surfaces, and the image beam is reflected by the reflective surfaces and outputs from the projection screen.

Abstract: A projection system including a projection apparatus and a screen is provided. The projection apparatus is adapted to output a plurality of exciting beams respectively having a plurality of different wavebands. The screen is disposed on a transmission path of the exciting beams. The screen includes a plurality of fluorescence material layers and at least one gas barrier layer. The fluorescence material layers are adapted to be excited by the exciting beams to emit image beams respectively having different wavebands, so as to form an image frame. The gas barrier layer covers the fluorescence material layers.