Illuminating unit and projection display apparatus

Abstract

An illuminating unit of the disclosure includes a light source, a plurality of optical members for illumination that guide light from the light source to a predetermined optical path, and a polarization split element that transfers, to a predetermined illuminating position, a first polarized component included in the light guided to the predetermined optical path. One or more of the plurality of optical members for illumination have optical properties, for the light at a predetermined wavelength band outputted from the light source, of guiding the first polarized component to the predetermined optical path, and guiding a second polarized component that is different from the first polarized component toward a direction deviated from the predetermined optical path.

1 . An illuminating unit, comprising:
 a light source;   a plurality of optical members that guide light from the light source to an optical path;   a panel that receives the light guided from the light source; and   a polarization split element that receives the light through the panel to an external device.   
     
     
         2 . The illuminating unit according to  claim 1 , wherein the light source comprises a plurality of light sources that are disposed on different optical paths from each other, the plurality of optical members for illumination include an optical path combination element that combines the optical paths of two or more of the plurality of light sources, and in combining the optical paths, the optical path combination element has optical properties, for the light at the predetermined wavelength band, of guiding the first polarized component to the predetermined optical path, and guiding the second polarized component toward the direction deviated from the predetermined optical path. 
     
     
         3 . The illuminating unit according to  claim 2 , wherein the first polarized component is S-polarized light with respect to the polarization split element, and the second polarized component is P-polarized light with respect to the polarization split element. 
     
     
         4 . The illuminating unit according to  claim 3 , wherein the optical path combination element has polarizing properties of reflecting the first polarized component and transmitting the second polarized component for light at a first wavelength band serving as the light at the predetermined wavelength band, and has properties of transmitting light at a second wavelength band. 
     
     
         5 . The illuminating unit according to  claim 3 , wherein the optical path combination element has polarizing properties of transmitting the first polarized component and reflecting the second polarized component for light at a first wavelength band serving as the light at the predetermined wavelength band, and has properties of reflecting light at a second wavelength. 
     
     
         6 . The illuminating unit according to  claim 3 , wherein the polarization split element transfers the first polarized component to the predetermined illuminating position by reflection. 
     
     
         7 . The illuminating unit according to  claim 2 , wherein the first polarized component is P-polarized light with respect to the polarization split element, and the second polarized component is S-polarized light with respect to the polarization split element. 
     
     
         8 . The illuminating unit according to  claim 7 , wherein the optical path combination element has polarizing properties of reflecting the first polarized component and transmitting the second polarized component for light at a first wavelength band serving as the light at the predetermined wavelength band, and has properties of transmitting light at a second wavelength band. 
     
     
         9 . The illuminating unit according to  claim 7 , wherein the optical path combination element has polarizing properties of transmitting the first polarized component and reflecting the second polarized component for light at a first wavelength band serving as the light at the predetermined wavelength band, and has properties of reflecting light at a second wavelength. 
     
     
         10 . The illuminating unit according to  claim 7 , wherein the polarization split element transfers the first polarized component to the predetermined illuminating position by transmission. 
     
     
         11 . The illuminating unit according to  claim 2 , wherein an incoming angle of the light at the predetermined wavelength band that enters the optical path combination element from the light source is at least 25 degrees but no more than 75 degrees. 
     
     
         12 . The illuminating unit according to  claim 1 , wherein
 the light through the panel includes a first polarized component and a second polarized component.   
     
     
         13 . The illuminating unit according to  claim 1 , wherein
 the polarization split element transfers, to a predetermined illuminating position, a first polarized component included in the light guided to the predetermined optical path.   
     
     
         14 . The illuminating unit according to  claim 1 , wherein
 one or more of the plurality of optical members have optical properties, for the light at a predetermined wavelength band outputted from the light source, of guiding the first polarized component to the predetermined optical path, and guiding a second polarized component that is different from the first polarized component toward a direction deviated from the predetermined optical path.