Illumination optical system and projector including fluorophore
An illumination optical system includes: a light source emitting light of a first wavelength; a fluorophore unit; an optical element and a quarter-wave plate between the optical element and the fluorophore unit. The fluorophore unit has a reflection region and a fluorophore region that gives off fluorescent light of a different wavelength than the first wavelength when irradiated by light of the first wavelength. The fluorophore unit is able to move such that the light from the light source sequentially irradiates the fluorophore region and the reflection region. The optical element separates the light of the first wavelength into a first linearly polarized light component and a second linearly polarized light component that is orthogonal to the first linearly polarized light component. The optical element guides the first linearly polarized light component of the light emitted from the light source to the fluorophore unit, and emits the light of the first wavelength that was reflected by the reflection region and fluorescent light that was emitted by the fluorophore region in the same direction.
1. An illumination optical system comprising:
a light source emitting light of a first wavelength;
a fluorophore unit including a reflection region reflecting light of said first wavelength and a fluorophore region including a fluorophore emitting fluorescent light of a wavelength that differs from said first wavelength by the irradiation of light of said first wavelength, said fluorophore unit being capable of movement such that light from said light source is successively irradiated on said fluorophore region and said reflection region;
an optical element separating light of said first wavelength into a first linearly polarized light component and a second linearly polarized light component, the second linearly polarized light being orthogonal to said first linearly polarized light component, the optical element guiding said first linearly polarized light component emitted from said light source to said fluorophore unit, the optical element being again irradiated by light reflected on said reflection region and by light emitted from said fluorophore region; and
a quarter-wave plate provided on the light path between said optical element and said fluorophore unit, wherein
said optical element emits light of said first wavelength that was reflected by said reflection region and said fluorescent light that was emitted by said fluorophore region in the same direction.
2. The illumination optical system according to claim 1 , wherein said first linearly polarized light component of light from said light source passes through said quarter-wave plate and is converted to circularly polarized light, and said circularly polarized light is then irradiated into said fluorophore unit.
3. The illumination optical system according to claim 1 , wherein said optical element reflects said first linearly polarized light component of light of said first wavelength and transmits said fluorescent light and said second linearly polarized light component of light of said first wavelength.
4. The illumination optical system according to claim 3 , wherein said first linearly polarized light component comprises an S-polarized light component that is orthogonal to the incidence plane on said optical element, and said second linearly polarized light component comprises a P-polarized light component that is parallel to said incidence plane.
5. The illumination optical system according to claim 1 , wherein said optical element transmits said first linearly polarized light component of light of said first wavelength and reflects said fluorescent light and said second linearly polarized light component of light of said first wavelength.
6. The illumination optical system according to claim 5 , wherein said first linearly polarized light component comprises a P-polarized light component that is parallel to the incidence plane on said optical element and said second linearly polarized light component comprises an S-polarized light component that is orthogonal to said incidence plane.
7. The illumination optical system according to claim 1 , wherein said light source comprises a laser that emits blue light having said first linearly polarized light component.
8. The illumination optical system according to claim 1 , further comprising a motor driving said fluorophore unit to rotate around an axis of rotation, the axis of rotation being orthogonal to one surface on which are provided said reflection region and said fluorophore region.
9. The illumination optical system according to claim 1 , wherein said phosphor region includes a first region that, by irradiation of light of said first wavelength, emits fluorescent light of a second wavelength that is longer than said first wavelength, and a second region that, by irradiation of light of said first wavelength, emits fluorescent light of a third wavelength that is longer than said second wavelength.
10. A projector including the illumination optical system according to claim 1 .
11. The illumination optical system according to claim 2 , wherein said optical element reflects said first linearly polarized light component of light of said first wavelength and transmits said fluorescent light and said second linearly polarized light component of light of said first wavelength.
12. The illumination optical system according to claim 11 , wherein said first linearly polarized light component comprises an S-polarized light component that is orthogonal to the incidence plane on said optical element, and said second linearly polarized light component comprises a P-polarized light component that is parallel to said incidence plane.
13. The illumination optical system according to claim 2 , wherein said optical element transmits said first linearly polarized light component of light of said first wavelength and reflects said fluorescent light and said second linearly polarized light component of light of said first wavelength.
14. The illumination optical system according to claim 13 , wherein said first linearly polarized light component comprises a P-polarized light component that is parallel to the incidence plane on said optical element and said second linearly polarized light component comprises an S-polarized light component that is orthogonal to said incidence plane.