A polarizing beam splitting system is described. The polarizing beam splitting system may include first and second prisms where the volume of the first prism is no greater than half the volume of the second prism. The first prism includes first and second surfaces and a light source may be disposed adjacent the first surface and an image forming device may be disposed adjacent the second surface. The first prism has a first hypotenuse and the second prism has a second hypotenuse. A reflective polarizer is disposed between the first and second hypotenuses.

An illumination system, including a laser light source, a wavelength conversion module, and a polarization conversion unit, and a projection device are provided. A laser beam of the laser light source is converted to a wavelength conversion beam by a wavelength conversion region of the wavelength conversion module. The polarization conversion unit has multiple first polarization conversion regions and multiple second polarization conversion regions, and includes multiple phase delay sheets correspondingly located on multiple surfaces facing the laser light source and located in the second polarization conversion regions. The wavelength conversion beam with a second polarization state leaves the polarization conversion unit after passing through a surface of the polarization conversion unit in the first polarization conversion regions facing the laser light source. The wavelength conversion beam with a first polarization state leaves the polarization conversion unit after passing through the phase delay sheet in the second polarization conversion region.

An illumination system, including a light source module, a phosphor wheel, a light recycling element, and a light uniformizing element, is provided. The light source module emits an excitation light beam. The phosphor wheel includes a phosphor region. At a second timing, the other part of the excitation light beam transmitted to the phosphor region forms an unconverted light beam and is transmitted to the light recycling element, and is reflected by the light recycling element to form a recycled light beam. A part of the recycled light beam is converted into a second converted light beam. A first converted light beam and the second converted light beam are transmitted to the light uniformizing element through a same path, so that the illumination system outputs second light in the illumination light beam. A projection apparatus is also provided.

A structured light projector includes a light source configured to emit light, a structured light pattern mask configured to receive the light emitted by the light source and including a first region configured to generate a first structured light having a first polarization and a second region configured to generate a second structured light having a second polarization that is different from the first polarization, and a polarization multiplexing deflector configured to deflect the first structured light and the second structured light generated by the structured light pattern mask, to different directions, respectively.

An optical system of a semi-vertical single LCD (liquid crystal display) projector includes a projection light source, a condenser, an illuminating reflector, a collimating lens, a heat reflecting glass, an LCD light valve, a field lens, an imaging reflector and a projection lens, all of which are set in sequence according to a direction of light, wherein the illuminating reflector reflects and turns light irradiating the LCD light valve in up and down directions, and the imaging reflector performs mirror reflection and turning on light emitted by the LCD light valve in left and right directions. The present invention obtains a new optical system structure, creates a novel stacking and a novel projector appearance, and has low cost, small size and complete integration.

A light source apparatus includes a plurality of light emitting apparatuses. Each of the light emitting apparatuses includes a plurality of light emitting devices each of which has a light emitting area and a non-light emitting area on an emission surface thereof that emits light. At least two light emitting apparatuses of the light emitting apparatuses constitute a light emitting apparatus group disposed such that the emission surfaces of the respective light emitting apparatuses are parallel to each other with a predetermined distance, and that a distance between light emitting areas of the respective light emitting apparatuses when viewed along a direction perpendicular to the emission surfaces of the at least two of the light emitting apparatuses is shorter than a distance between the light emitting areas of the respective light emitting apparatuses when the emission surfaces of the respective light emitting apparatuses are on the same plane.

A light source device includes a first light source configured to emit first color light, a wavelength conversion element configured to convert a wavelength of excitation light made incident thereon and emit converted light having a wavelength larger than the wavelength of the excitation light, and an emission-position changing mechanism configured to change an emission position of the incident excitation light to thereby change an incident position of the excitation light on the wavelength conversion element and change an emission position of the first color light and an emission position of the converted light in the same direction in synchronization with each other.

In a display device, when blue (B) light enters a first liquid crystal panel, radiated light radiated from the first liquid crystal panel contains red (R) phosphorescence having a wavelength range longer than blue (B) light due to a deterioration of a liquid crystal material. Thus, in the display device, an optical sensor device is provided behind a mirror comprised of a dichroic mirror to monitor or the like the service life of the first liquid crystal panel on the basis of a result of reception, at the optical sensor device, of light having a frequency band ranging from 600 nm to 650 nm, and makes notification of the result. Furthermore, on the basis of a result from the optical sensor device, an electrode used to suck impurities provided at the first liquid crystal panel is driven to sweep ionic impurities from a display region.

An illumination system, an illumination control method and a projection apparatus are provided. The illumination system includes a first laser light source providing a first laser beam, and a light splitting module. When the first laser beam is incident to the light splitting module, a first portion of the first laser beam penetrates through the light splitting module, a second portion is reflected by the light splitting module. In the first illumination mode, the first laser beam is incident to the first light splitting region to form a first proportion of the first portion and the second portion. In the second illumination mode, the first laser beam is incident to the first light splitting region to form a second proportion of the first portion and the second portion, wherein the first proportion and the second proportion are different.

A light-source optical system includes a wavelength converter on which light of first color is incident, the wavelength converter converting at least a part of the light of first color into light of second color different from the light of first color, a first optical system disposed upstream from the wavelength converter on an optical path of the light of first color, the first optical system including optical elements, a reflection plane disposed downstream from the first optical system on the optical path, and a second optical system disposed downstream from the reflection plane on the optical path. The reflection plane reflects one of the light of first color and the light of second color, and a conditional expression “0<ΔL/D<0.2” is satisfied.