Patent ID: 7236300

Claim:
A transmission type screen comprising: a fly-eye lens comprising lens unit cells each of which has a convex lens shape on one side thereof; and a light-shielding layer provided on an opposite side of a lens surface of said fly-eye lens and having a plurality of openings provided near each focus of said lens unit cells, wherein a cross-section of each of said lens unit cells in a horizontal direction when said screen is used, the cross-section passing a center of each of said lens unit cells, is an arbitrary convex lens shape with respect to an area provided between a first lens curve, wherein when uniform light parallel to an optical axis of said lens unit cell is incident upon the lens surface, luminance on an emission side of said screen is highest in an optical axis direction of said lens unit cell, and a distance in the optical axis direction on the cross-section of said lens unit cell from an intersection between an effective lens surface of said lens unit cell and the optical axis to a boundary with an adjacent one of said lens unit cells is longest, and a second lens curve, wherein when said screen is observed on the emission side, luminance when said screen is observed from a direction inclined against the optical axis direction by a maximum horizontal viewing angle predetermined in a horizontal direction is a proportion of a reference, which is less than one, to luminance when said screen is observed from the optical axis direction, the area including the second lens curve, and a cross-section of each of said lens unit cells in a vertical direction when said screen is used, the cross-section passing the center of each of said lens unit cells, is an arbitrary convex lens shape with respect to an area provided between the second lens curve and a third lens curve, wherein when uniform light parallel to the optical axis is incident upon the lens surface, luminance on the emission side when said screen is observed from a direction inclined against the optical axis direction by a maximum vertical viewing angle, which is predetermined in the vertical direction and less than the maximum horizontal viewing angle, is a proportion of the reference as compared to the luminance when the screen is observed from the optical axis direction, the area not including the second lens curve.