| 摘要 |
PROBLEM TO BE SOLVED: To provide a focus adjustment mechanism that allows a focus to be adjusted without using a complicate control or structure in an optical telescope.SOLUTION: A focus adjustment mechanism according to the present invention has: a link rod that rotates with a base end as a rotation shaft; an oscillation mechanism that has a shaft guiding a tip end of the link rod so as to oscillate the tip end thereof; a first spring that has one end connected to the base end, and has the other end connected to a mirror stand for anchoring a reflection mirror; and a second spring that has a spring coefficient higher than the that of the first spring, has one end connected to the mirror stand and has the other end connected to the oscillation mechanism. The link rod is rotated by a displacement of the tip end oscillating along the shaft, the rotation of the link rod ignites a generation of a displacement in the base end, and first urging force is given to the first spring due to the displacement generated in the base end. The second spring is displaced with second urging force in a direction cancelling out the first urging force given by the first urging force, and the mirror stand is displaced in a displacement direction of the second spring by being guided with the second spring.SELECTED DRAWING: Figure 2 |
