| 摘要 |
PROBLEM TO BE SOLVED: To enable idling of a polarization filter in the installed state of the installed part of the frame body of the polarization filter in a lens barrel or the installing part of another frame body.SOLUTION: In an installing part 21 of a protective filter frame body 2, a female screw part 22 having a first chevron and an installing side non-screw part 23 having no first chevron are continuously provided from a side where a polarization filter 10 is installed. In the installed part 11 of a polarization filter frame body 1, from the side of installing in a protective filter 20, a male screw part 12 having a second chevron engaged with the first chevron of the female screw part 22 and having a length corresponding to the axial length of the installing side non-screw part 23 and an installed side non-screw part 13 having no second chevron part and having a length corresponding to the axial length of the female screw part 22 are continuously provided. The male screw part 12 is continuously screwed into the female screw part 22 until its engaged state with the female screw part 22 is released, and housed in the installing side non-screw part 23. Thus, idling of the polarization filter 10 is enabled. |
