Light source device, illumination optical device, and projector
A light source device configured to emit a light beam in a first direction includes a first exit position from which a first colored light beam is emitted, a second exit position from which a second colored light beam is emitted, a third exit position from which a third colored light beam is emitted, and a fourth exit position from which a fourth colored light beam is emitted, at least one of the first through fourth colored light beams is a target colored light beam which has a peak wavelength out of a reference wavelength range, and a beam diameter of which is to be adjusted, an adjusting element disposed on a light path of the target colored light beam.
1. A light source device configured to emit a light beam in a first direction, comprising:
a first exit position from which a first colored light beam is emitted;
a second exit position which is located at a second direction side of the first exit position, and from which a second colored light beam is emitted;
a third exit position which is located at a third direction side of the first exit position, and from which a third colored light beam is emitted; and
a fourth exit position which is located at the second direction side of the third exit position, and from which a fourth colored light beam is emitted, wherein
the second direction and the third direction are perpendicular to the first direction, and are perpendicular to each other,
at least one of the first colored light beam, the second colored light beam, the third colored light beam, and the fourth colored light beam is a target colored light beam which has a peak wavelength out of a reference wavelength range, and a beam diameter of which is to be adjusted,
an adjusting element is disposed in a light path of the target colored light beam, and
the adjusting element is one of
a diameter reduction element configured to reduce the beam diameter of the target colored light beam when the target colored light beam has the peak wavelength longer than an upper limit value of the reference wavelength range, and
a diameter expansion element configured to expand the beam diameter of the target colored light beam when the target colored light beam has the peak wavelength shorter than a lower limit value of the reference wavelength range.
2. The light source device according to claim 1 , wherein
the diameter reduction element is one of a convex lens and a concave mirror, and
the diameter expansion element is one of a concave lens and a convex mirror.
3. The light source device according to claim 1 , wherein
out of the first colored light beam, the second colored light beam, the third colored light beam, and the fourth colored light beam,
one is a green light beam,
one is a red light beam,
one is a blue light beam, and
one is one of a green light beam and a yellow light beam.
4. The light source device according to claim 3 , wherein
one of the first colored light beam and the second colored light beam is the blue light beam,
another of the first colored light beam and the second colored light beam is one of the green light beam and the yellow light beam,
one of the third colored light beam and the fourth colored light beam is the green light beam, and
another of the third colored light beam and the fourth colored light beam is the red light beam.
5. The light source device according to claim 4 , wherein
the reference wavelength range is included in a wavelength region of the green light beam,
the diameter reduction element is disposed in a light path of the red light beam as the other of the third colored light beam and the fourth colored light beam, and
the diameter expansion element is disposed in a light path of the blue light beam as the one of the first colored light beam and the second colored light beam.
6. The light source device according to claim 5 , wherein
the other of the first colored light beam and the second colored light beam is the yellow light beam, and
the diameter reduction element is disposed in a light path of the yellow light beam as the other of the first colored light beam and the second colored light beam.
7. The light source device according to claim 5 , wherein
the other of the first colored light beam and the second colored light beam is the green light beam, and
a blocking element configured to transmit the green light beam and block another colored light beam is disposed in a light path of the green light beam as the other of the first colored light beam and the second colored light beam.
8. The light source device according to claim 1 , further comprising:
a first color separation element configured to separate the first colored light beam and the second colored light beam from a light beam including the first colored light beam and the second colored light beam; and
a second color separation element configured to separate the third colored light beam and the fourth colored light beam from a light beam including the third colored light beam and the fourth colored light beam.
9. The light source device according to claim 8 , wherein
the adjusting element is disposed in the light path of the target colored light beam separated by a color separation element configured to separate the target colored light beam out of the first color separation element and the second color separation element.
10. The light source device according to claim 9 , wherein
the adjusting element is integrated with the color separation element configured to separate the target colored light beam out of the first color separation element and the second color separation element.
11. The light source device according to claim 8 , wherein
the first color separation element includes
a first color separation layer configured to transmit the first colored light beam, and reflect the second colored light beam, and
a first reflecting layer located at the second direction side of the first color separation layer, and configured to reflect the second colored light beam reflected by the first color separation layer in parallel to the first colored light beam transmitted through the first color separation layer, and
the second color separation element includes
a second color separation layer configured to transmit the third colored light beam, and reflect the fourth colored light beam, and
a second reflecting layer located at the second direction side of the second color separation layer, and configured to reflect the fourth colored light beam reflected by the second color separation layer in parallel to the third colored light beam transmitted through the second color separation layer.
12. The light source device according to claim 11 , wherein
when the adjusting element is disposed in a light path of the first colored light beam, the first color separation layer is provided to a plane of incidence of light of the adjusting element,
when the adjusting element is disposed in a light path of the second colored light beam, the first reflecting layer is provided to the plane of incidence of light of the adjusting element,
when the adjusting element is disposed in a light path of the third colored light beam, the second color separation layer is provided to the plane of incidence of light of the adjusting element, and
when the adjusting element is disposed in a light path of the fourth colored light beam, the second reflecting layer is provided to the plane of incidence of light of the adjusting element.
13. The light source device according to claim 8 , further comprising:
a light source section configured to emit a source light beam;
a first polarization split element configured to transmit a first polarization component of the source light beam in the third direction, and reflect a second polarization component of the source light beam in an opposite direction to the first direction out of the source light beam emitted from the light source section and enters the first polarization split element along the third direction;
a second polarization split element located at the third direction side of the first polarization split element, and configured to reflect the first polarization component of the source light beam entering the second polarization split element in the third direction toward the opposite direction to the first direction;
a first reflecting element located in the opposite direction side to the first direction side of the first polarization split element, and configured to reflect the source light beam entering the first reflecting element toward the first direction;
a first retardation element located between the first polarization split element and the first reflecting element in the first direction, and configured to convert a polarization component of the source light beam;
a wavelength conversion element located at the opposite direction side to the first direction side of the second polarization split element, and configured to emit a converted light beam as unpolarized light, which is obtained by performing wavelength conversion on the first polarization component of the source light beam entering the wavelength conversion element in the opposite direction to the first direction, toward the first direction;
a second retardation element which is a ½ wave plate located in the light path of the first colored light beam separated by the first color separation element, and converts a polarization direction of the first colored light beam and then emits the first colored light beam; and
a third retardation element which is a ½ wave plate which is located at the first direction side of the second polarization split element, and which the converted light beam transmitted through the second polarization split element enters, wherein
the second polarization split element transmits the first polarization component of the converted light beam in the first direction to thereby make the first polarization component enter the third retardation element, and reflects the second polarization component of the converted light beam toward an opposite direction to the third direction out of the converted light beam entering the second polarization split element in the first direction,
the first polarization split element transmits the first polarization component of the source light beam entering the first polarization split element in the first direction toward the first direction to thereby make the first polarization component enter the first color separation element, and reflects the second polarization component of the source light beam entering the first polarization split element in the opposite direction to the third direction toward the first direction to thereby make the second polarization component enter the first color separation element,
the first color separation element is located at the first direction side of the first polarization split element, emits the first polarization component of the source light beam entering the first color separation element from the first polarization split element to the second retardation element, and emits the second polarization component of the converted light beam entering the first color separation element from the first polarization split element, and
the second color separation element is located at the first direction side of the third retardation element, emits a first color component included in the second polarization component of the converted light beam entering the second color separation element from the third retardation element, and emits a second color component included in the second polarization component of the converted light beam.
14. An illumination optical device comprising:
the light source device according to claim 1 ;
a pair of multi-lenses configured to divide the light beam entering the pair of multi-lenses from the light source device into a plurality of partial light beams; and
a superimposing lens configured to superimpose the plurality of partial light beams entering the superimposing lens from the pair of multi-lenses on a predetermined position.
15. A projector comprising:
the illumination optical device according to claim 14 ;
a light modulation device configured to modulate light emitted from the illumination optical device; and
a projection optical device configured to project the light modulated by the light modulation device, wherein
the light modulation device includes
a single liquid crystal panel having a plurality of pixels, and
a microlens array which has a plurality of microlenses corresponding to the plurality of pixels, and is located at a light incident side of the single liquid crystal panel,
the pixels each include a first sub-pixel, a second sub-pixel, a third sub-pixel, and a fourth sub-pixel, and
the plurality of microlenses makes
the first colored light beam enter the first sub-pixels,
the second colored light beam enter the second sub-pixels,
the third colored light beam enter the third sub-pixels, and
the fourth colored light beam enter the fourth sub-pixels.