Light source device and projector

A light source device comprising:

• a light emission element;
• a polarization separation element on which a light emitted from the light emission element is incident, and that separates the light into a first component of light polarized in a first direction and a second component of light polarized in a second direction perpendicular to the first direction;
• a phase difference element on which the first component of light is incident, and that converts the first component of light to a circularly polarized light;
• a condensing optical system on which the circularly polarized light is incident;
• an optical element on which the circularly polarized light transmitted through the condensing optical system is incident, wherein
• the polarization separation element is provided on a light path between the light emission element and the condensing optical system,
• the phase difference element is provided on a light path between the polarization separation element and the condensing optical system,
• the optical element includes a reflection surface from which the circularly polarized light is reflected,
• the circularly polarized light reflected from the reflection surface is incident on the condensing optical system,
• the circularly polarized light transmitted through the condensing optical system is incident on the phase difference element, and that is converted to a third component of light polarized in the second direction,
• the third component of light is incident on the polarization separation element,
• the condensing optical system includes a first lens and a third lens, the first lens being formed of quartz,
• the first lens is disposed at a position closest to the optical element in the condensing optical system,
• the third lens is disposed at a position closest to the base difference element in the condensing optical system, and
• a photoelastic constant of the third lens is less than a photoelastic, constant of the first lens.

A light source device comprising:

• a light emission element;
• a polarization separation element on which a light emitted from the light emission element is incident, and that separates the light into a first component of light polarized in a first direction and a second component of light polarized in a second direction perpendicular to the first direction;
• a phase difference element on which the first component of light is incident, and that converts the first component of light to a circularly polarized light;
• a condensing optical system on which the circularly polarized light is incident;
• an optical element on which the circularly polarized light transmitted through the condensing optical system is incident, wherein
• the polarization separation element is provided on a light path between the light emission element and the condensing optical system,
• the phase difference element is provided on a light path between the polarization separation element and the condensing optical system,
• the optical element includes a reflection surface from which the circularly polarized light is reflected,
• the circularly polarized light reflected from the reflection surface is incident on the condensing optical system,
• the circularly polarized light transmitted through the condensing optical system is incident on the phase difference element, and that is converted to a third component of light polarized in the second direction,
• the third component of light is incident on the polarization separation element,
• the condensing optical system includes a first lens and a second lens, the first lens being formed of quartz,
• the first lens is disposed at a position closest to the phase difference element in the condensing optical system,
• the second lens is disposed at a position closest to the optical element in the condensing optical system,
• the second lens is formed of quartz,
• the second lens has a curve surface with a radius of curvature of 1000 mm or more or a planar surface on a side of the optical element,
• the second lens has a spherical surface on a side facing away from the optical element, and
• an absolute value of a curvature of the spherical surface is greater than an absolute value of a curvature of the curve surface or the planar surface.

A light source device comprising:

• a light emission element;
• a polarization separation element on which a light emitted from the light emission element is incident, and that separates the light into a first component of light polarized in a first direction and a second component of light polarized in a second direction perpendicular to the first direction;
• a phase difference element on which the first component of light is incident, and that converts the first component of light to a circularly polarized light;
• a condensing optical system on which the circularly polarized light is incident;
• an optical element on which the circularly polarized light transmitted through the condensing optical system is incident, wherein
• the polarization separation element is provided on a light path between the light emission element and the condensing optical system,
• the phase difference element is provided on a light path between the polarization separation element and the condensing optical system,
• the optical element includes a reflection surface from which the circularly polarized light is reflected,
• the circularly polarized light reflected from the reflection surface is incident on the condensing optical system,
• the circularly polarized light transmitted through the condensing optical system is incident on the phase difference element, and that is converted to a third component of light polarized in the second direction,
• the third component of light is incident on the polarization separation element,
• the condensing optical system includes a first lens and a third lens, the first lens being formed of quartz,
• the first lens is disposed at a position closest to the optical element in the condensing optical system,
• the first lens has a curve surface with a radius of curvature of 1000 mm or more or a planar surface on a side of the optical element,
• the first lens has a spherical surface on a side facing away from the optical element, and
• an absolute value of a curvature of the spherical surface is greater than an absolute value of a curvature of the curve surface or the planar surface.