Wavelength plate, polarization conversion device using the same, illumination optical system, and image display apparatus

1. Optical apparatus comprising:

an integrator device which reduces illuminance unevenness of light received from a light source and includes a plurality of lenses;

a polarization conversion device which is disposed in an optical path of light which passes through the integrator device, and includes a wavelength plate comprising:

a first quartz plate unit including a plurality of quartz plates which have main surfaces disposed in the same plane, at least the first and second quartz plates of the first unit being jointed with each other end-to-end; and

a second quartz plate unit including a plurality of quartz plates which have main surfaces disposed on a main surface of the first quartz plate unit, at least the first and second quartz plates of the second unit being jointed with each other end-to-end in a position different from the end-to-end joint position of the first quartz plate unit,

wherein a boundary of adjacent lenses in the plurality of lenses of the integrator device is disposed between two closest joints among joints of the first quartz plate unit and the second quartz plate unit when seen from an optical axis direction of the integrator device.

2. The optical apparatus according to claim 1 ,

wherein the quartz plates which form the first quartz plate unit exhibit a length that differs from the length of the quartz plates which form the second quartz plate unit.

3. The wavelength plate optical apparatus according to claim 2 ,

wherein all the plurality of quartz plates which form the second quartz plate unit have the same length.

4. Optical apparatus according to claim 3 ,

wherein, in the second quartz plate unit, a quartz plate which is larger than the quartz plates which form the first quartz plate unit, and a quartz plate which is smaller than the quartz plates which form the first quartz plate unit are alternately jointed with each other.

5. An illumination optical system comprising:

a light source;

an integrator device which reduces illuminance unevenness of light emitted from the light source; and

a polarization conversion device which is disposed in an optical path of light which passes through the integrator device, and includes a polarization splitting device which splits incident light into p-polarized light and s-polarized light and a wavelength plate which is disposed in an optical path of any one polarized light split by the polarization splitting device,

wherein the wavelength plate of the polarization conversion device includes a first quartz plate unit including a plurality of quartz plates which have main surfaces disposed in the same plane and are jointed with each; and a second quartz plate unit including a plurality of quartz plates which have main surfaces disposed on a main surface of the first quartz plate unit and are jointed with each other in a position different from a joint position of the first quartz plate unit,

wherein a boundary of adjacent lenses in a plurality of lenses which form the integrator device is disposed between two closest joints among joints of the first quartz plate unit and the second quartz plate unit when seen from an optical axis direction of the integrator device.

6. A illumination optical system comprising:

a light source;

an integrator device which reduces illuminance unevenness of light emitted from the light source; and

a polarization conversion device which is disposed in an optical path of light which passes through the integrator device, and includes a polarization splitting device which splits incident light into p-polarized light and s-polarized light and a wavelength plate which is disposed in an optical path of any one polarized light split by the polarization splitting device,

wherein the wavelength plate of the polarization conversion device includes a first quartz plate unit including a plurality of quartz plates which have main surfaces disposed in the same plane and are jointed with each; and a second quartz plate unit including a plurality of quartz plates which have main surfaces disposed on a main surface of the first quartz plate unit and are jointed with each other in a position different from a joint position of the first quartz plate unit, and

wherein the joints of the first quartz plate unit and the second quartz plate unit are disposed in a line extended in the optical axis direction from a boundary of adjacent lenses in the plurality of lenses which form the integrator device.

7. An image display apparatus comprising:

an illumination optical system including a light source, an integrator device which reduces illuminance unevenness of light emitted from the light source and includes a plurality of lenses, and a polarization conversion device which is disposed in an optical path of light which passes through the integrator device and includes a polarization splitting device which splits incident light into p-polarized light and s-polarized light and a wavelength plate which is disposed in an optical path of any one polarized light split by the polarization splitting device;

a spectroscopic optical system which disperses light emitted from the illumination optical system;

a liquid crystal panel which modulates each dispersed light;

a light synthesizing section which synthesizes the light modulated by the liquid crystal panel; and

a lens which projects the light synthesized by the light synthesizing section,

wherein the wavelength plate of the illumination optical system includes a first quartz plate unit including a plurality of quartz plates which have main surfaces disposed in the same plane, at least the first and second quartz plates of the first unit being jointed with each other end-to-end; and a second quartz plate unit including a plurality of quartz plates which have main surfaces disposed on a main surface of the first quartz plate unit, at least the first and second quartz plates of the second unit being jointed with each other end-to-end in a position different from the end-to-end joint position of the first quartz plate unit, and

wherein the joints of the first quartz plate unit and the second quartz plate unit are disposed in a line extended in the optical axis direction from a boundary of adjacent lenses in the plurality of lenses of the integrator device.