Patent ID: 8149360
Filing Date: 2012-04-03
Classification: H04N

Abstract:
1. A projection image display apparatus, comprising: a light source; a polarizing beam splitter having a polarizing beam splitting surface through which one polarized light in incident light passes and which reflects the other polarized light in the incident light which is orthogonal to the one polarized light; an image display element for modulating the incident light into image light and reflecting the image light; a first retardation plate disposed between the polarizing beam splitter and the image display element; and a projection lens for projecting the image light onto a screen, wherein: the first retardation plate has refractive indices different from each other between two directions orthogonal to each other in an optical surface of the first retardation plate, and gives a phase difference which is larger than λ/4 to polarized light which vertically enters the optical surface and has a wavelength λ in a used wavelength band; and when coordinate axes are defined so that a direction of a normal to a light entering/exiting surface of the polarizing beam splitter is a z axis, a direction which is perpendicular both to the z axis and to a normal to the polarizing beam splitting surface is a y axis, and a direction which is perpendicular both to the z axis and to the y axis is an x axis, the first retardation plate has an optic axis which is within an xz plane and is tilted with respect to the x axis.