Patent ID: 8593704

Claim:
An erecting equal-magnification lens array plate comprising: a first lens array plate provided with a plurality of first lenses systematically arranged on a first surface and a plurality of second lenses systematically arranged on a second surface opposite to the first surface; and a second lens array plate provided with a plurality of third lenses systematically arranged on a third surface and a plurality of fourth lenses systematically arranged on a fourth surface opposite to the third surface; wherein the first lens array plate and the second lens array plate form a stack such that the second surface and the third surface face each other to ensure that a combination of the lenses aligned with each other form a coaxial lens system, and an erect equal-magnification image of an object on the first surface side on an image plane facing the fourth surface, the erecting equal-magnification lens array plate further comprising: a fourth surface light-shielding wall provided with a plurality of fourth surface through holes corresponding to the fourth lenses and provided on the fourth surface such that the fourth surface through holes are located directly opposite to the corresponding fourth lenses; and an intermediate light-shielding wall provided with a plurality of intermediate through holes corresponding to the second and third lenses and provided between the first lens array plate and the second lens array plate such that the intermediate through holes are located directly opposite to the corresponding second and third lenses, wherein the intermediate through hole is formed such that the hole diameter is progressively smaller in a tapered fashion away from the second surface toward the third surface, and an angle of inclination θ of an interior wall surface of the intermediate through hole with respect to a optical axis is given by θ≧tan −1 ( D 4/(Gap+ L 2+ H 4))/2, where Gap denotes a gap between the first lens array plate and the second lens array plate, L 2 denotes a thickness of the second lens array plate, H 4 denotes a height of the fourth surface light-shielding wall, and D 4 denotes a diameter of the opening of the fourth surface through hole facing the image plane.