| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens array having heat resistance which suppresses change in a conjugate length even if the lens array is used under a high temperature environment, and also to provide a rod lens used for the array. SOLUTION: The plastic rod lens has a columnar shape, having a refractive index that continuously decreases from the center to the outer circumference, and having a heat contraction starting temperature of≥80°C when the temperature is elevated at the temperature rising rate of 4°C/min. The invention includes a manufacturing method of a second plastic rod lens for which the first plastic rod lens manufactured through a fiber forming step, a drawing step and a relaxing step is heat treated for one hour or longer, at a temperature≤100°C but not lower than the heat contraction starting temperature when heated at the temperature rising rate of 4°C/min. COPYRIGHT: (C)2007,JPO&INPIT |
