Patent ID: 8678595
Filing Date: 2014-03-25
Classification: G03B

Abstract:
1. A projection type display apparatus, comprising: a light source; a display element; an illumination optical system comprising a plurality of optical elements to enter light from the light source and to emit the light to the display element; and a projection lens to magnify an optical image formed by the display element and to project a magnified image of the optical image, wherein the illumination optical system comprises: a first array lens and a second array lens each includes a plurality of lens elements arranged in a matrix, each of the lens elements having a rectangular shape opening, and a polarization conversion element having a polarization conversion function to convert a polarization direction of light incident thereon into a predetermined polarization direction of light and to emit polarized light by use of a plurality of polarized beam splitters and a plurality of half-wave phase plates, the beam splitters and the phase plates being arranged in an array and opposing to the lens elements of the second array lens, and wherein the light source comprises a light emitting plane having substantially a rectangle or an ellipse shape, a longitudinal direction of the shape of the light emitting plane being parallel to a longitudinal direction of each opening of the polarization conversion element, wherein, a ratio of the longitudinal length of the display element to the vertical length thereof is M/N (M>N), and a ratio of a length in the longitudinal direction of the light emitting plane of the light source to a length in the vertical direction thereof is less than (4N×N)/(M×M).