Patent ID: 6831706
Filing Date: 2004-12-14
Classification: G02B,H04N

Abstract:
A projection image display apparatus comprisingan illumination optical system which illuminates an image display element with light from a light source and a projection optical system which projects light from the image display element through two polarization split surfaces, wherein when an occurrence ratio of leakage light on one polarization split surface with respect to a light ray having a wavelength &lgr; is represented by analysis performance K(&lgr;), relative visibility of the human eye is represented by Y(&lgr;), and a wavelength region of light rays incident on said one polarization split surface is represented by a range of &lgr;1 to &lgr;2, a value M given by M=&Integral;Î»1Î»2&it;Y&it;(Î»)&it;K&af;(Î»)&it;â€ƒ&it;&dd;Î»/&Integral;Î»1Î»2&it;Y&it;(Î»)&it;â€ƒ&it;&dd;Î»is set as a leakage light amount on the polarization split surface, light rays, of the light rays incident on the polarization split surface, of which angles with respect to an optical axis correspond to 55% of a maximum angle of the incident light rays with respect to the optical axis and which are incident on one of the two polarization split surfaces which is located on the image display element side at largest and smallest angles are set as first and second light rays, respectively, and L<0.006 is satisfied when a light shielding characteristic value L on the two polarization split surfaces is represented by L=[(M1)aÂ·(M1)b+(M2)aÂ·(M2)b]/2 where(M1)a is the amount of leakage light of the first light ray on the polarization split surface on the image display element side, (M2)a is the amount of leakage light of the second light ray on the polarization split surface on the image display element side, (M1)b is the amount of leakage light of the first light ray on the polarization split surface on the projection optical system side, and (M2)b is the amount of leakage light of the second light ray on the polarization split surface on the projection optical system side.