Patent ID: 6724537
Filing Date: 2004-04-20
Classification: G02B

Abstract:
A lens array for unity magnification imaging, comprising:a plurality of rod lenses arranged in at least one row at a lens arrangement pitch D, each rod lens having an angle of aperture &thgr;, the lens arrangement pitch D being defined to satisfy the following equation (1): (2 m+1)Â·D&lE;2.1 mmâ€ƒâ€ƒ(1), wherein m is an overlap degree of the plurality of rod lenses, the angle of aperture &thgr; of the rod lens being defined to satisfy the following equation (2): &agr;D/6Ã—{nÂ·cosâˆ’1(âˆ’&agr;/2/m)+(4 m2/&agr;2âˆ’1)1/2}&lE;&thgr;&lE;&agr;D/2Ã—(4 m2/&agr;2âˆ’1)1/2â€ƒâ€ƒ(2), wherein n is a refractive index on an optical axis of the rod lens, d is an effective diameter of the rod lens, &agr; is a filling factor of the lens array, the overlap degree m is set in a range of 1.53 to 3.00 when the plurality of rod lenses are arranged in odd-numbered rows, and the overlap degree is set in a range of 1.10 to 3.00 when the plurality of rod lenses are arranged in even-numbered rows.