| 摘要 |
PROBLEM TO BE SOLVED: To provide a focal plane shutter and an optical device which have occurrence of dust suppressed.SOLUTION: A focal plane shutter comprises: a base plate; a curtain; an electromagnet; a drive lever which has an iron piece to be adsorbed and held by the electromagnet, and is slidably supported to the base plate; a drive arm which is coupled to the drive lever, slidably supported to the base plate and drives the curtain; an energizing member that energizes the drive lever in such a way that the iron piece separates from the electromagnet, and causes the curtain to be travelled; a ratchet wheel 50B which engages with the energizing member to enable adjustments of the energizing force of the energizing member; and a lock member 130b which includes a pawl part 131 allowing the ratchet wheel 50B to stop at a prescribed position. The ratchet wheel 50B is composed of a tooth row part 51 having a plurality of teeth allowed to be engaged with by the pawl part 131 partially formed in an outer periphery of the ratchet wheel 50B, and a curve part 52 in which the teeth are not formed and the pawl part 131 is slidable, to suppress occurrence of dust. |
