Patent ID: 8014072
Filing Date: 2011-09-06
Classification: G02B

Abstract:
1. An erecting equal-magnification lens array plate including a stack of a plurality of individual lens array plates built such that pairs of corresponding lenses form a coaxial lens system, where each individual lens array plate is formed with a plurality of lenses on one or both surfaces of the individual lens array plate, the erecting equal-magnification lens array plate receiving light from a substantially straight light source facing one side of the erecting equal-magnification lens array plate, and the erecting equal-magnification lens array plate forming an erect equal-magnification image of the substantially straight light source on an image plane facing the other side of the erecting equal-magnification lens array plate, wherein a light shielder operative to shield light not contributing to imaging is formed in a neighborhood of a position in the intermediate plane in the erecting equal-magnification lens array plate where an inverted image of the substantially straight light source is formed, a main lens arrangement direction differs from a main scanning direction of the erecting equal-magnification lens array plate, the light shielder restricts a light transmitting region of each lens such that lens regions outside a slit opening, which is substantially parallel with the main scanning direction, are totally prevented from transmitting light, and given that the individual lens array plate has a plate thickness t, the lens's working distance is denoted by WD, and the individual lens array plate has a refractive index n, and a distance between the center of the lens and a reference plane perpendicular to the erecting equal-magnification lens array plate and substantially parallel with the main scanning direction is denoted by y