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Patent Searching and Data


Title:
ILLUMINATING DEVICE AND PROJECTION TYPE DISPLAY DEVICE
Document Type and Number:
Japanese Patent JP2009216754
Kind Code:
A
Abstract:

To provide a bright illuminating device having high illumination efficiency by decreasing the loss of light rays as compared to a conventional illuminating device.

The illuminating device is equipped with a light source part 5 comprising a light source 4 and a catoptric system 3 reflecting luminous flux emitted from the light source 4 and taking it out in one direction, a phase modulation part 2 changing a polarization direction of luminous flux, and a polarized light splitting part 1 splitting the luminous flux having the different polarization direction to transmitted light and reflected light, wherein the phase modulation part 2 is arranged to cover a part 6A that is an almost half of cross section 6 of all the luminous flux reflected by the catoptric system of the light source part 5, and is constituted to include optical paths A1 to A10 where the luminous flux emitted from the light source part 5 passes through both the phase modulation part 2 and the polarized light splitting part 1 and is emitted as illuminating light, and optical paths B1 to B3 where the luminous flux emitted from the light source part 5 does not pass through the phase modulation part 2 but passes only through the polarized light splitting part 1 and is emitted as illuminating light.


Inventors:
Fujita, Kazuhiro
Nagase, Osamu
Application Number:
JP2008000057340
Publication Date:
September 24, 2009
Filing Date:
March 07, 2008
Export Citation:
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Assignee:
RICOH CO LTD
RICOH OPT IND CO LTD
International Classes:
G03B21/14; F21S2/00; F21V13/00; G02B27/28; G02F1/13; G02F1/13357; G02F1/13363; G03B21/00