Projection apparatus

A projection apparatus, comprising:

• a light source for emitting illumination light;
• a condensing lens for condensing the illumination light emitted from said light source;
• a first polarizing plate for adjusting polarized light components of the illumination light having passed through said condensing lens;
• a first polarization rotating element for rotating the polarization plane of the illumination light in the wavelength band of green from within the illumination light whose polarized light components have been adjusted by said first polarizing plate;
• demultiplexing means for reflecting the illumination light in the wavelength band of green whose polarization plane has been rotated by said first polarization rotating element and passing the illumination light in wavelength bands of red and blue therethrough;
• a second polarization rotating element for rotating the polarization plane of the illumination light in a first one of the wavelength bands of red and blue from within the illumination light having passed through said demultiplexing means and passing the illumination light in a second one of the wavelength bands of red and blue therethrough;
• a first optical modulation element for modulating and reflecting the illumination light in the second wavelength band having passed through said second polarization rotating element;
• a second optical modulation element for modulating and reflecting the illumination light in the first wavelength band whose polarization plane has been rotated by said second polarization rotating element;
• a third optical modulation element for modulating and reflecting the illumination light in the wavelength band of green reflected by said demultiplexing means;
• a first polarization beam splitter interposed between said second polarization rotating element and said first and second optical modulation elements for passing the illumination light in the second wavelength band having passed through said second polarization rotating element so as to be introduced to said first optical modulation element and reflecting the illumination light in the first wavelength band whose polarization plane has been rotated by said second polarization rotating element so as to be introduced to said second optical modulation element and for reflecting the modulated and reflected light in the second wavelength band from said first optical modulation element and passing the modulated and reflected light in the first wavelength band from said second optical modulation element therethrough;
• a third polarization rotating element for passing the reflected light in the second wavelength band reflected by said first polarization beam splitter therethrough and rotating the polarization plane of the reflected light in the first wavelength band having passed through said first polarization beam splitter;
• a second polarization beam splitter interposed between said demultiplexing means and said third optical modulation element for reflecting the illumination light in the wavelength band of green reflected by said demultiplexing means so as to be introduced to said third optical modulation element and passing the modulated reflected light in the wavelength band of green from said third optical modulation element therethrough;
• a third polarization beam splitter for reflecting the reflected light in the second wavelength band having passed through said third polarization rotating element, reflecting the reflected light in the first wavelength band whose polarization plane has been rotated by said third polarization rotating element and passing the reflected light in the wavelength band of green having passed through said second polarization beam splitter therethrough;
• and
• a projection lens for projecting the reflected light in the first wavelength band reflected by said third polarization beam splitter, the reflected light in the second wavelength band reflected by said third polarization beam splitter and the reflected light in the wavelength band of green having passed through said third polarization beam splitter so as to form a screen image of an enlarged scale.