| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress aberration caused by the tensile stress of adhesive agent on a first lens 11 and a second lens 12 toward a lens barrel, even when using the first glass lens 11 and the second resin lens 12 for an objective lens 5, and to avoid the performance deterioration of the objective lens 5. <P>SOLUTION: A communication part 21 is disposed in the lens barrel 13 which holds the first lens 11 and the second lens 12. The communication part 21 is prepared for making a gap part 14 formed between the first lens 11 and the second lens 12 communicate with the outside, and the communication part 21 is arranged in the lens barrel 13 so that the gap part 14 may communicate with the outside through a part of the outer peripheral surface of the first lens 11. Thus, even if the tensile stress on the first lens 11 toward the lens barrel 13 by the adhesive agent is unequally applied in the peripheral direction (direction around optical axis) of the first lens 11 when the first lens 11 is stuck and fixed to the lens barrel 13 with the adhesive agent, the first glass lens 11 is hard and hardly deforms, then, the occurrence of the aberration can be suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
