A light-emitting apparatus and a related projection system. The light-emitting apparatus comprises an excitation light source generating an excitation light and a first supplemental laser source generating a first light; a wavelength conversion apparatus comprising a first wavelength conversion layer for absorbing the excitation light to generate a converted light without absorbing the first light; the wavelength conversion layer receiving at one side thereof the excitation light and the first light and emits at same side at least a portion of the first light; a light guide apparatus comprising a smaller first area and a larger second area, the first light and the excitation light respectively entering the first and second areas via a first optical path, and being respectively guided by the first and second areas to the wavelength conversion apparatus; the second area also guiding the converted light and the reflected first light to a second optical path.

The light source is based on a high-efficiency solid-state laser source of the excitation coherent radiation and a single crystal phosphor which is machined in a form of an optic element for emitted light parameterisation. The single crystal phosphor is produced from a single crystal material on the basis of garnets of the (A.sub.x, Lu.sub.1-x).sub.aAl.sub.bO.sub.12:Ce.sub.c general formula or from a single crystal material on the basis of perovskite structure of the B.sub.1-qAlO.sub.3:D.sub.q general formula. The efficient light source shall be utilized e.g. in the automotive industry.

An object of the present invention is to provide a fluorescent light source apparatus that is capable of efficiently cooling a fluorescent member and holding the fluorescent member at a proper position relative to a reflector and is thus capable of stably providing a high light output over a long period of time. A fluorescent light source apparatus according to the present invention has a configuration in which a fluorescent member that generates fluorescence upon application of excitation light thereto and a reflector having a reflective surface disposed so as to face an excitation light receiving surface of the fluorescent member are held by a common holding structure formed of a heat conductive material. The holding structure includes a cylindrical base part, and a heat conducting part formed so as to extend from an inner circumferential surface of the base part toward a center axis of the base part. The fluorescent member is held so as to be positioned on the center axis of the base part, on a side surface of the heat conducting part of the holding structure, the side surface facing the reflective surface of the reflector.

A light-source optical system according to the present invention includes a laser light source that radiates excitation light; a wavelength conversion unit that is irradiated with the excitation light to generate light having a wavelength different from that of the excitation light; and a light deflection and convergence unit that causes an odd number of light beams greater than or equal to three, radiated from the wavelength conversion unit in mutually different directions, to converge at and re-enter the wavelength conversion unit from the backward direction of another light beam, radiated in a direction different from the directions of the odd number of light beams greater than or equal to three, thereby making the odd number of light beams greater than or equal to three overlap the other light beam.

A light-source optical system according to the present invention includes a laser light source that radiates excitation light; a wavelength conversion unit that is irradiated with the excitation light to generate light having a wavelength different from that of the excitation light; and a light deflection and convergence unit that causes an odd number of light beams greater than or equal to three, radiated from the wavelength conversion unit in mutually different directions, to converge at and re-enter the wavelength conversion unit from the backward direction of another light beam, radiated in a direction different from the directions of the odd number of light beams greater than or equal to three, thereby making the odd number of light beams greater than or equal to three overlap the other light beam.

The present invention relates to a filament (100) comprising a light transmissive tubular member (110), a light emitting assembly (106) arranged within the tubular member (110), a wavelength converter (112) arranged at a surface of the tubular member (110) and configured to convert light from a first wavelength range to a second wavelength range. The light emitting assembly (106) comprises a plurality of solid state light sources (102) and interconnecting elements (104) being arranged in an alternating manner to form a string (106) of connected solid state light sources (102) and interconnecting elements (104). The interconnecting elements are portions of a lead frame (104) and at least a part of the plurality of solid state light sources (102) are arranged on opposite sides of the lead frame (104) in an alternating manner. The inventive filament (100) is simple, easy and cheap to manufacture, thus providing a good replacement and approximation for an incandescent wire.

An illumination optical system with a tunable beam angle (IOSTBA) is presented to achieve different beam angles without changing parts. The IOSTBA includes a light source and a post having a proximal end and a distal end, the proximal end in optical communication with the light source, an internal area of the post having a reflective surface. Also shown is a diffuser disposed across the end of the post, the diffuser in optical communication with the post and a reflector surrounding a portion of the post, the reflector movable along a length of the post. A position of the reflector along the post determines a beam angle of a resulting light beam exiting the IOSTBA. The system features a simple and cost effective optical design which works with a variety of light sources, including color mixing and champing strategies.

A wavelength conversion element includes: a wavelength conversion layer; a light-transmissive member provided on a light-incident surface side of the wavelength conversion layer and including a support surface including an inclined portion inclined with respect to the light-incident surface; and a first reflection portion provided along the support surface and reflecting fluorescence light. The first reflection portion includes a dichroic film that transmits excitation light. The excitation light passes through the dichroic film and the light-incident surface in this order to enter the wavelength conversion layer. Defining a plane including the light-incident surface as a reference surface, a distance between the reference surface and the first reflection portion in a periphery region of the first reflection portion is smaller than a distance between the reference surface and the first reflection portion in a central region of the first reflection portion.

A wavelength conversion element includes: a wavelength conversion layer; a light-transmissive member provided on a light-incident surface side of the wavelength conversion layer and including a support surface including an inclined portion inclined with respect to the light-incident surface; and a first reflection portion provided along the support surface and reflecting fluorescence light. The first reflection portion includes a dichroic film that transmits excitation light. The excitation light passes through the dichroic film and the light-incident surface in this order to enter the wavelength conversion layer. Defining a plane including the light-incident surface as a reference surface, a distance between the reference surface and the first reflection portion in a periphery region of the first reflection portion is smaller than a distance between the reference surface and the first reflection portion in a central region of the first reflection portion.

A phosphor wheel includes: a substrate; a light reflection layer disposed on one surface of the substrate; a phosphor layer; and a bonding layer which is located between and bonds the light reflection layer and the phosphor layer, wherein the bonding layer contains a particle which is higher in thermal conductivity than a base material of the bonding layer and higher in light reflectance than the light reflection layer.