Rod lens array and equal-magnification imaging optical apparatus using rod lens array
AssigneeMitsubishi Rayon Co., Ltd.
InventorsMasashi IIMORI, Shingo INUZUKA
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Abstract
A rod lens array is configured so that when a relation between R and r0 is set to be R≧r0≧0.8R, and the gradient index of the rod lens is approximate to n(r)2=n02{1−(g·r)2}, an overlap degree m, defined by m=X0/2R, is 2.55 or more and 4 or less and an aperture angle of the rod lens, represented by n0·g·r0, is 0.1 or more and less than 0.22. The array is capable of minimizing light quantity unevenness even where there may be assembly error or aged deterioration occurs. An equal-magnification imaging optical apparatus usefully includes a rod lens array.
Claims14
A rod lens array configured by arranging a plurality of rod lenses each having a gradient index in a radial direction in one row with a predetermined arrangement pitch so that the optical axes of the rod lenses are parallel to each other,
- wherein light quantity unevenness ΔE is 10% or less, and
- wherein resolution MTF measured by using a lattice pattern with a spatial frequency of 6 line pairs/mm is 85% or more.
A rod lens array configured by arranging a plurality of rod lenses each having a gradient index in a radial direction in one row with an interval of arrangement pitch 2R so that optical axes of the rod lenses are parallel to each other,
- wherein, when a relation between R and r0 is set to be R≦r0≦0.8R and the gradient index of the rod lens is approximate to n(r)2=n02{1−(g·r)2}, an overlap degree m defined by m=X0/2R is more than 2.5 and an aperture angle of the rod lens represented by n0·g·r0 is 0.1 or more and less than 0.22, and
- wherein r represents a distance from an optical axis, n(r) represents a refractive index at a position of the distance r from the optical axis, n0 represents a refractive index at the center of the rod lens, g represents a gradient index constant, X0 represents a radius of field of view (X0=−r0 cos(Z0π/P)), r0 represents an effective radius of the rod lens, Z0 represents a length of the rod lens, and P represents a period length (P=2π/g) of the rod lens.
Dependencies are inferred from the claim text.