| 摘要 |
PROBLEM TO BE SOLVED: To increase accuracy in the arrangement of lens elements at a low cost and to prevent decrease in the resolution of a rod lens array. SOLUTION: The rod lens array 10 has such a structure that many rod lens elements 16 are arranged in lines between two side plates 14 and integrated by filling the gap with a resin. The side plate consists of a glass plate and has a flat smooth surface facing the lens elements, whereas a reflection suppressing part 20 is formed on the opposite outer surface. A light shielding zone 22 is formed on the exiting side face of each glass plate from the outer edge to the inner part and almost all over the length of the face. The width Ts of the light shielding zone satisfies Tg>Ts> Tg-Z×D×2+√3×(n-1)}/ 2×(TC-Z}}, wherein Tg is the thickness of the glass plate, D is the diameter of the lens element, Z is the length of the lens element, TC is the conjugate length and n is the number of lines of the lens elements. The glass plate may be made thin instead of forming the light shielding zone.
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