Illumination device and projector

An illumination device comprising:

• a solid-state light source device;
• a pickup lens unit adapted to control a proceeding direction of light input from the solid-state light source device;
• and
• a polarization conversion element adapted to align a polarization direction of light emitted from a light exit surface of the pickup lens unit, wherein
• a lens constituting the light exit surface of the pickup lens unit is an aspherical lens having a light exit surface shaped like a rotationally symmetric shape centered on a light axis of the pickup lens unit when viewed from a direction of the light axis of the pickup lens unit, and having a cross-section of an aspherical shape when cut with a plane parallel to the light axis,
• the light exit surface of the aspherical lens has a function of collimating and then emitting light emitted from a center of the solid-state light source device in an area relatively near to the light axis, and emitting light from an outer peripheral area relatively far from the light axis of the pickup lens unit so as to converge toward the light axis of the pickup lens unit,
• the axis of the light emitted from the outer peripheral area of the light exit surface of the aspherical lens is inclined with respect to the light axis of the pickup lens unit,
• the light emitted from the outer peripheral area of the light exit surface of the aspherical lens gets closer to the light axis of the pickup lens unit as the light travels toward the polarization conversion element,
• the polarization conversion element includes a first region that emits illumination light traveling along a first light path and a second region that emits illumination light traveling along a second light path,
• the length of the second light path is longer than the length of the first light path,
• the polarization conversion element is configured so as to cancel out the intensity difference caused by the difference in light path length between the illumination light emitted from the first region and the illumination light emitted from the second region to thereby enhance the in-plane uniformity of the illumination light intensity,
• the first light path includes traveling through a polarization splitting film,
• the second light path includes traveling so as to be reflected by a total reflection prism, and
• a part of the light emitted from the outer peripheral area proceeds in the dispersing direction with a small spread angle and then directly enters the internal total reflection prism without entering the polarization splitting film.

An illumination device comprising:

• a solid-state light source device;
• a pickup lens unit adapted to control a proceeding direction of light input from the solid-state light source device;
• and
• a polarization conversion element adapted to align a polarization direction of light emitted from an inner peripheral area of a light exit surface of the pickup lens unit, and an outer peripheral area of the light exit surface of the pickup lens unit, wherein
• a lens constituting the light exit surface of the pickup lens unit is an aspherical lens having a light exit surface shaped like a rotationally symmetric shape centered on a light axis of the pickup lens unit when viewed from a direction of the light axis of the pickup lens unit, and having a cross-section of an aspherical shape when cut with a plane parallel to the light axis,
• the light exit surface of the aspherical lens has a function of collimating and then emitting light emitted from a center of the solid-state light source device in an area relatively near to the light axis of the pickup lens unit in a direction parallel to the light axis of the pickup lens unit, and emitting obliquely with respect to the light axis of the pickup lens unit light from an outer peripheral area of the light exit surface, which is relatively far from the light axis of the pickup lens unit so as to converge toward the light axis of the pickup lens unit,
• the axis of the light emitted from the outer peripheral area of the light exit surface of the aspherical lens is inclined with respect to the light axis of the pickup lens unit,
• the light emitted from the outer peripheral area of the light exit surface of the aspherical lens gets closer to the light axis of the pickup lens unit as the light travels toward the polarization conversion element,
• the polarization conversion element is composed of two optical blocks each with the same configuration composed of a polarization beam splitter provided with a polarization splitting film, and an internal total reflection prism provided with a total reflection film, and
• the optical blocks are disposed symmetrically about the illumination light axis of the illumination device.