Abstract: 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<?L/D<0.2” is satisfied.

Abstract: A light-source device includes an excitation light source; a wavelength conversion unit to convert at least some of first color light into second color light; a light mixing element including a rod integrator to mix at least one of the first color light and the second color light from the conversion unit; and an optical element on an optical path of the first color light and having a reflecting surface. A center of the first color light on the reflecting surface intersects with only one of a first light flux of the first color light incident on and a second light flux of the first color light emitted from the conversion unit. An angle formed by a projection straight line of the first color light incident on an incident aperture of the integrator and a predetermined axial line of the incident aperture of the integrator is smaller than 40°.

Abstract: A light guide optical device includes an optical path combiner including: a first deflector to deflect first light incident from a first direction to an emission direction; a second deflector to deflect second light incident from a second direction different from the first direction, to the emission direction; and a transmission portion between the first deflector and the second deflector, the transmission portion to transmit third light incident from a third direction different from each of the first direction and the second direction, to the emission direction. The optical path combining unit combines the first light, the second light, and the third light, and emits the combined light to the mission direction.

Abstract: A light-source device includes an excitation light source to emit first color light; an optical member having a reflecting surface to reflect the first color light; a wavelength conversion unit including a wavelength conversion member on which the first color light reflected by the optical member is incident, the wavelength conversion member to convert at least part of the first color light into second color light having a wavelength different from a wavelength of the first color light and emit the second color light; and a light condensing element to condense the first color light emitted from the wavelength conversion unit. A straight line including a first optical path from a center of a flux of light rays emitted from the excitation light source, to the center of the first color light on the reflecting surface does not intersect with a light flux condensed by the light condensing element.

Abstract: A light source device includes: a first light source to emit first color light; a second light source to emit second color light; a wavelength conversion unit to convert at least a portion of the first color light into a third color light; a light incident element to which the first color light, the second color light, and the third color light enter; a first filter to reflect the first color light toward the wavelength conversion unit; and a second filter to reflect the second color tight toward the light incident element. The first filter and the second filter are separately disposed on an optical path of the third color light between the wavelength conversion unit and the light incident element.

Abstract: A light source device includes a light source, a plurality of wavelength conversion units, and a plurality of optical systems. The plurality of wavelength conversion units each includes a wavelength conversion region configured to receive light emitted from the light source and emit light with a wavelength different from a wavelength of the received light. The plurality of optical systems are configured to form images of wavelength conversion regions of the plurality of wavelength conversion units. The light source is configured to irradiate the wavelength conversion units with light at a same timing. The plurality of optical systems are configured to cause the images of the wavelength conversion regions of the plurality of wavelength conversion units to be adjacent to or superimposed on each other.

Abstract: A light source device includes: multiple light source units each including a light source to emit a first color light beam, each of the multiple light source units configured to: convert at least part of the first color light beam into a second color light beam emitted from an emitting region; and emit the second color light beam to form a conjugate image; and a light combiner to combine the conjugate images formed by the multiple light source units to form a combined image, in which the conjugate images partially overlap each other, on a plane of an entrance surface of a light uniformizing element along a central axis of the light uniformizing element. A conditional expression below is satisfied: 1.3>SC/SI>0.7 where SC is an area of the combined image, and SI is an area of the entrance surface of the light uniformizing element.

Abstract: A light source optical system includes: a first optical system configured to guide a first light beam having a first wavelength emitted from a light source to a wavelength conversion element; the wavelength conversion element configured to convert the first light beam into a second light beam having a second wavelength different from the first wavelength, and emit the second light beam; and a second optical system through which the second light beam emitted from the light conversion element passes. The second optical system includes a light guide element configured to guide a portion of the second light beam from one end surface of the light guide element to the other end surface of the light guide element to separate the portion of the second light beam from the second light beam.

Abstract: A light source optical system includes a wavelength conversion unit configured to receive first color light emitted from by an excitation light source and emit second color light with a wavelength different from a wavelength of the first color light; and a first optical system and a second optical system provided in an optical path between the excitation light source and the wavelength conversion unit. The first optical system includes one optical element having a negative power, wherein the second optical system as a whole has a positive power, and wherein Conditional Expression (1) is satisfied as follows: 1.8<|Fn/F2|<5.0,??(1) where Fn is a focal length for a d-line of the optical element having the negative power of the first optical system, and F2 is a focal length for the d-line of the second optical system.

Abstract: An image projection apparatus includes: a light source; an image display element including multiple micromirrors arranged in two dimensions, the multiple micromirrors forming an image display plane, each micromirror having a reflecting surface; and a projection optical system. Conditional expressions (1) and (2) below are satisfied: ?1?14 (deg)??(1) 1.2<BF/L<2.2??(2) where ?1 is a maximum tilt angle of the reflecting surface of each micromirror with respect to the image display plane, L is a diagonal length of the image display plane, and BF is a distance between a vertex of a lens within the projection optical system and closest to the image display plane and the image display plane along an optical axis of the projection optical system.

Abstract: A light source optical system used with an excitation light source configured to emit first color light includes a wavelength conversion unit configured to receive the first color light emitted by the excitation light source and emit second color light with a wavelength different from a wavelength of the first color light, There is a first optical system having a positive power and a second optical system having a positive power provided in this order in an optical path between the excitation light source and the wavelength conversion unit. When a ray parallel to an optical axis of the first optical system is incident on the first optical system, a ray emitted from the first optical system is incident on the second optical system while approaching the optical axis. The second optical system has under-corrected spherical aberration at a paraxial focal position of the second optical system.

Abstract: A light-source device includes an excitation light source; a wavelength conversion unit to convert at least some of first color light into second color light; a light mixing element including a rod integrator to mix at least one of the first color light and the second color light from the conversion unit; and an optical element on an optical path of the first color light and having a reflecting surface. A center of the first color light on the reflecting surface intersects with only one of a first light flux of the first color light incident on and a second light flux of the first color light emitted from the conversion unit. An angle formed by a projection straight line of the first color light incident on an incident aperture of the integrator and a predetermined axial line of the incident aperture of the integrator is smaller than 40°.

Abstract: There is provided a projection optical system capable of projecting an image formed on an image forming unit on a projection plane, which has an extremely short projection distance and a small size.

Abstract: A light source optical system includes a wavelength conversion unit configured to receive first color light emitted from by an excitation light source and emit second color light with a wavelength different from a wavelength of the first color light; and a first optical system and a second optical system provided in an optical path between the excitation light source and the wavelength conversion unit. The first optical system includes one optical element having a negative power, wherein the second optical system as a whole has a positive power, and wherein Conditional Expression (1) is satisfied as follows: 1.8<|Fn/F2|<5.0,??(1) where Fn is a focal length for a d-line of the optical element having the negative power of the first optical system, and F2 is a focal length for the d-line of the second optical system.

Abstract: A light-source device includes an excitation light source, an optical member, and a wavelength converter. The excitation light source is configured to emit first color light. The optical member has a reflecting surface configured to reflect the first color light emitted from the excitation light source. The wavelength converter includes a wavelength conversion member on which the first color light reflected by the optical member is incident. The wavelength conversion member is configured to convert at least part of the first color light into second color light having a wavelength different from a wavelength of the first color light and emit the second color light. A center of the first color light on the reflecting surface of the optical member does not intersect with a light flux of the first color light emitted from the wavelength converter.

Abstract: An optical system includes a reflective optical system on a magnification side along an optical path of the projection optical system and a refractive optical system on a reduction side along the optical path. The reflective optical system includes one reflective optical element having a power. The refractive optical system includes a front group on the magnification side and a rear group on the reduction side. The front group having, in order from the magnification side toward the reduction side, a first lens group with a positive or negative refractive power, a second lens group, and a third lens group with a positive refractive power. The rear group has a positive refractive power. The first lens group moves to the magnification side, and the second lens group and the third lens group move to the reduction side in a change in focus from a long distance to a short distance.

Abstract: A light source optical system includes a wavelength conversion unit configured to receive first color light emitted from by an excitation light source and emit second color light with a wavelength different from a wavelength of the first color light; and a first optical system and a second optical system provided in an optical path between the excitation light source and the wavelength conversion unit. The first optical system includes one optical element having a negative power, wherein the second optical system as a whole has a positive power, and wherein Conditional Expression (1) is satisfied as follows: 1.8<|Fn/F2|<5.0,??(1) where Fn is a focal length for a d-line of the optical element having the negative power of the first optical system, and F2 is a focal length for the d-line of the second optical system.

Abstract: A projection optical system satisfies ?1?15 (deg) and 3<EP/Ym<7. ?1 is a maximum inclination angle of the reflective surface of each of the micromirrors with respect to the line normal to the image display surface; EP is an entrance pupil distance of the projection optical system; and Ym is a maximum distance in a plane from an optical axis to a point on the image display surface, the plane being a plane in which a light ray propagating from a center of the image display surface toward the projection surface through a center of an aperture stop of the projection optical system exists, the optical axis being an axis shared by a largest number of the plurality of lenses of the projection optical system, the point corresponding to an image on the projection surface.

Abstract: A light-source device includes an excitation light source; an optical element having a reflecting surface to reflect first colored light emitted from the excitation light source; and a wavelength conversion unit including a waveform conversion member configured to convert at least a portion of the first colored light reflected by the optical element and incident on the wavelength conversion unit, into second colored light having a wavelength different from a wavelength of the first colored light and emit the second colored light. A point P does not intersect with a light flux Q where the point P is a center of the first colored light on the reflecting surface of the optical element and the light flux Q is a light flux of the first colored light emitted from the wavelength conversion unit.

Abstract: A light source optical system includes a wavelength conversion unit configured to receive first color light emitted from by an excitation light source and emit second color light with a wavelength different from a wavelength of the first color light; and a first optical system and a second optical system provided in an optical path between the excitation light source and the wavelength conversion unit. The first optical system includes one optical element having a negative power, wherein the second optical system as a whole has a positive power, and wherein Conditional Expression (1) is satisfied as follows: 1.8<|Fn/F2|<5.0,??(1) where Fn is a focal length for a d-line of the optical element having the negative power of the first optical element, and F2 is a focal length for the d-line of the second optical system.