| 摘要 |
PURPOSE: To prevent the invasion of dust and light by providing an integratedly formed airtight material at an adjusting slit. CONSTITUTION: An integratedly formed airtight tongue part 7 is constituted of a series of thin plates 9 which is arranged to face in a direction crossing with the longitudinal axis 8 of the adjusting slit 3 at interval in an opposite side. The thin plates 9 are linked in a bridge shape by a wall 10 cutting-off intermediate space 11 towards the invading direction C of the adjusting slit 3 and formed to be thicker than the walls 10. When the thin plates 9 are deformed by mechanical activation, for example, by an adjusting material 4 passing a side, they wants to get back to an original position by specific force and only the thin plates 9 which is energized by the adjusting material 4 are normally deformed. The adjacent thin plates 9 are at the normal positions where the adjusting material 4 is buried and the interval is not formed in the penetrating direction of the adjusting slit 3 by the end surface 16. |
