Abstract: A light source apparatus includes light sources emitting first and second polarized light, an optical element transmitting one of the polarized light and reflecting the other, a polarization rotator generating polarization rotated light from the first polarized light, a wavelength convertor converting the second polarized light into wavelength converted light, and a controller. The optical element generates emitted light by combining the wavelength converted light and polarization rotated light. The controller acquires respective deterioration amounts of the light sources, and controls, based on respective changes in light emission amounts from the light sources acquired from the deterioration amounts, the light emission amount from at least one of the light sources for making different respective change amounts of the light emission amounts from the light sources, or changing a ratio between respective light emission amounts from the light sources.

Abstract: A light source apparatus includes a first solid light source, a second solid light source configured to emit light with a wavelength different from that from the first solid light source, and a controller configured to control turning on of the first and second solid light sources. The controller turns on the second solid light source while maintaining turning on the first solid light source after turning on the first solid light source.

Abstract: A wavelength conversion element includes a wavelength conversion layer configured to convert light having a first wavelength into light having a second wavelength, and a flattening layer formed on at least one surface of the wavelength conversion layer. The flattening layer has a surface roughness smaller than that of the wavelength conversion layer. The wavelength conversion layer is made of a sintered body obtained by sintering a phosphor material and a ceramic material.

Abstract: A wavelength conversion element made of a sintered body includes a fluorescent member, a light-transmitting member having a thermal conductivity higher than that of the fluorescent member, and a light-scattering member having a refractive index higher than that of the light-transmitting member, and an average particle radius of 75 nm or more and 200 nm or less.

Abstract: A light source apparatus includes light sources emitting first and second polarized light, an optical element transmitting one of the polarized light and reflecting the other, a polarization rotator generating polarization rotated light from the first polarized light, a wavelength convertor converting the second polarized light into wavelength converted light, and a controller. The optical element generates emitted light by combining the wavelength converted light and polarization rotated light. The controller acquires respective deterioration amounts of the light sources, and controls, based on respective changes in light emission amounts from the light sources acquired from the deterioration amounts, the light emission amount from at least one of the light sources for making different respective change amounts of the light emission amounts from the light sources, or changing a ratio between respective light emission amounts from the light sources.

Abstract: A light source apparatus includes a red LD array that emits light in a red bandwidth, a blue LD array that emits light in a blue bandwidth, and a light combining part that includes a transmissive region and a reflecting region, the transmissive region transmitting the light emitted from the red LD array therethrough, the reflecting region reflecting the light emitted from the blue LD array.

Abstract: A light source apparatus includes a light source unit configured to emit light of a first wavelength, a first fluorescent element and a second fluorescent element each configured to convert at least part of the light of the first wavelength into light of a second wavelength that is different from the first wavelength, and a light amount adjustment unit configured to adjust an amount of light emitted to each of the first fluorescent element and the second fluorescent element. The first fluorescent element converts the light of the first wavelength into the light of the second wavelength at a first ratio. The second fluorescent element converts the light of the first wavelength into the light of the second wavelength at a second ratio that is different from the first ratio.

Abstract: An image projection apparatus includes a light source unit including a plurality of laser light sources, a light modulation element configured to modulate illumination light generated using a laser beam from the light source unit and to generate image light projected onto a projection surface, and a controller configured to control driving of the plurality of laser light sources. The controller controls a luminance of the illumination light by selecting a first laser light source that emits the laser beam and a second laser light source that does not emit the laser beam among the plurality of laser light sources.

Abstract: A light source apparatus includes a first light source configured to emit light in a first wavelength band, a second light source configured to emit light in a second wavelength band different from the first wavelength band, a light amount ratio changer configured to change a light amount ratio between a first polarized light component and a second polarized light component in light of the first wavelength band, a polarization beam splitter configured to split the first polarized light component and the second polarized light component, a wavelength converter configured to convert the light of the first wavelength band obtained from the first polarized light component, into light in a third wavelength band including the second wavelength band, and a light combiner configured to combine light in the first wavelength band and light in the second wavelength band with each other.

Abstract: The wavelength conversion element converts a wavelength of part of an exciting light to generate a fluorescent light and thereby generate a combined light in which the fluorescent light is combined with a non-converted light whose wavelength is the same as that of the exciting light. The element includes a fluorescent body, a binder contacting the fluorescent body, and multiple diffuser particles included in the binder. A minimum particle diameter of the multiple diffuser particles is ¼ or more and 4 times or less of a wavelength of the fluorescent light, and a ratio of a volume of the multiple diffuser particles to a total volume of the binder and multiple diffuser particles is 25% or more and 50% or less.

Abstract: A light source apparatus includes a red LD array that emits light in a red bandwidth, a blue LD array that emits light in a blue bandwidth, and a light combining part that includes a transmissive region and a reflecting region, the transmissive region transmitting the light emitted from the red LD array therethrough, the reflecting region reflecting the light emitted from the blue LD array.

Abstract: An image projection apparatus includes a light source unit including a plurality of laser light sources, a light modulation element configured to modulate illumination light generated using a laser beam from the light source unit and to generate image light projected onto a projection surface, and a controller configured to control driving of the plurality of laser light sources. The controller controls a luminance of the illumination light by selecting a first laser light source that emits the laser beam and a second laser light source that does not emit the laser beam among the plurality of laser light sources.

Abstract: A light source apparatus includes a first solid light source, a second solid light source configured to emit light with a wavelength different from that from the first solid light source, and a controller configured to control turning on of the first and second solid light sources. The controller turns on the second solid light source while maintaining turning on the first solid light source after turning on the first solid light source.

Abstract: An image projection apparatus includes a first light source configured to emit first light with a first wavelength band, a wavelength conversion element configured to convert part of the first light into wavelength-converted light with a wavelength band different from the first wavelength band and containing a second wavelength band, a second light source configured to emit second light with a wavelength band contained in the second wavelength band, a first measurement unit configured to measure a light quantity in a first measurement wavelength band as at least part of the second wavelength band, and an acquisition unit configured to acquire information on a light quantity of the first light and a light quantity of the second light by using a measurement result by the first measurement unit.

Abstract: An image projection apparatus includes a first light source configured to emit first light with a first wavelength band, a wavelength conversion element configured to convert part of the first light into wavelength-converted light with a wavelength band different from the first wavelength band and containing a second wavelength band, a second light source configured to emit second light with a wavelength band contained in the second wavelength band, a first measurement unit configured to measure a light quantity in a first measurement wavelength band as at least part of the second wavelength band, and an acquisition unit configured to acquire information on a light quantity of the first light and a light quantity of the second light by using a measurement result by the first measurement unit.

Abstract: An image display apparatus including a light source; a light source control unit configured to control electric power to be supplied to the light source; a light source cooling unit configured to cool the light source; a cooling control unit configured to control the light source cooling unit; an image display device; an illumination optical system configured to introduce light from the light source to the image display device, and a projecting optical system configured to project light modulated by the image display device. When the light source control unit receives a turn-off command, the light source control unit first lowers electric power to be supplied to the light source to a predetermined electric power lower than normal electric power to be supplied when the lamp is on, and then blocks the supply of the electric power to the light source, thereby turning the light source off.

Abstract: The wavelength conversion element converts a wavelength of part of an exciting light to generate a fluorescent light and thereby generate a combined light in which the fluorescent light is combined with a non-converted light whose wavelength is the same as that of the exciting light. The element includes a fluorescent body, a binder contacting the fluorescent body, and multiple diffuser particles included in the binder. A minimum particle diameter of the multiple diffuser particles is ¼ or more and 4 times or less of a wavelength of the fluorescent light, and a ratio of a volume of the multiple diffuser particles to a total volume of the binder and multiple diffuser particles is 25% or more and 50% or less.

Abstract: An image display apparatus including a light source; a light source control unit configured to control electric power to be supplied to the light source; a light source cooling unit configured to cool the light source; a cooling control unit configured to control the light source cooling unit; an image display device; an illumination optical system configured to introduce light from the light source to the image display device, and a projecting optical system configured to project light modulated by the image display device. When the light source control unit receives a turn-off command, the light source control unit first lowers electric power to be supplied to the light source to a predetermined electric power lower than normal electric power to be supplied when the lamp is on, and then blocks the supply of the electric power to the light source, thereby turning the light source off.

Abstract: An image display apparatus including a light source; a light source control unit configured to control electric power to be supplied to the light source; a light source cooling unit configured to cool the light source; a cooling control unit configured to control the light source cooling unit; an image display device; an illumination optical system configured to introduce light from the light source to the image display device, and a projecting optical system configured to project light modulated by the image display device. When the light source control unit receives a turn-off command, the light source control unit first lowers electric power to be supplied to the light source to a predetermined electric power lower than normal electric power to be supplied when the lamp is on, and then blocks the supply of the electric power to the light source, thereby turning the light source off.

Abstract: An image display apparatus including a light source; a light source control unit configured to control electric power to be supplied to the light source; a light source cooling unit configured to cool the light source; a cooling control unit configured to control the light source cooling unit; an image display device; an illumination optical system configured to introduce light from the light source to the image display device, and a projecting optical system configured to project light modulated by the image display device. When the light source control unit receives a turn-off command, the light source control unit first lowers electric power to be supplied to the light source to a predetermined electric power lower than normal electric power to be supplied when the lamp is on, and then blocks the supply of the electric power to the light source, thereby turning the light source off.