Optical element, polarization illumination device, and projector

An optical element comprising:

• a lens array composed of a plurality of lenses disposed in a matrix;
• and
• two polarization conversion element arrays, affixed to one surface of said lens array, the two polarization conversion element arrays converting polarized light with random polarization directions to one type of polarized light,
• wherein each of said polarization conversion element arrays include polarization separating surfaces for separating the polarized light with random polarization directions into two types of linearly polarized light and reflecting surfaces for reflecting one of the two types of the linearly polarized light produced by separation by said polarization separating surfaces, said polarization separating surfaces and said reflecting surfaces being alternately arranged between light-transmissive members, and
• wherein said two polarization conversion element arrays are separated by a predetermined space with no elements disposed between the two polarization conversion element arrays, said polarization separating surfaces of one of said two polarization conversion element arrays are arranged opposite to said polarization separating surfaces of the other of said two polarization conversion element arrays with respect to the predetermined space.

A polarization illumination device comprising:

• a light source;
• and
• an optical element for converting light from said light source into one type of polarized light, wherein said optical element includes a lens array composed of a plurality of lenses disposed in a matrix;
• and
• two polarization conversion element arrays, affixed to one surface of said lens array, for converting polarized light with random polarization directions to one type of polarized light,
• wherein each of said two polarization conversion element arrays includes polarization separating surfaces for separating the polarized light with random polarization directions into two types of linearly polarized light and reflecting surfaces for reflecting one of the two types of the linearly polarized light produced by separation by said polarization separating surfaces, said polarization separating surfaces and said reflecting surfaces being alternately arranged between light-transmissive members, and
• wherein said two polarization conversion element arrays are separated by a predetermined space with no elements disposed between the two polarization conversion element arrays, said polarization separating surfaces of one of said two polarization conversion element arrays are arranged opposite to said polarization separating surfaces of the other of said two polarization conversion element arrays with respect to the predetermined space.

A projection display apparatus projector comprising:

• a polarization illumination device;
• a modulating means for modulating device that modulates light from said polarization illumination device in accordance with a received image signal;
• and
• a projection optical means for projecting lens that projects the light beam modulated by said modulating means device,
• wherein said polarization illumination device includes a light source;
• and an optical element for converting light from said light source incident thereupon to light with a predetermined polarization direction that leaves said optical element, and
• wherein said optical element includes a lens array composed of a plurality of lenses disposed in a matrix;
• and
• two polarization conversion element arrays, affixed to one surface of said lens array, for converting polarized light with random polarization directions to one type of polarized light,
• wherein each of said two polarization conversion element arrays includes polarization separating surfaces for separating the polarized light with random polarization directions into two types of linearly polarized light and reflecting surfaces for reflecting one of the two types of the linearly polarized light produced by separation by said polarization separating surfaces, said polarization separating surfaces and said reflecting surfaces being alternately arranged between light-transmissive members, and
• wherein said two polarization conversion element arrays are separated by a predetermined space with no elements disposed between the two polarization conversion element arrays, said polarization separating surfaces of one of said two polarization conversion element arrays are arranged opposite to said polarization separating surfaces of the other of said two polarization conversion element arrays with respect to the predetermined space.