| 摘要 |
PROBLEM TO BE SOLVED: To reduce control sensitivity, for the case of a small aperture by a small operating angle of a drive ring by regarding a galvanometer enabling continuous drive as a driving source. SOLUTION: A pin 37a provided on a drive lever 37 for transmitting rotation drive of the drive galvanometer is rotated, up to the maximum of approximately 60 degrees in (a), and the drive ring 32 via a slot 32b of the drive ring 32, fitted with the pin 37a centers an optical axis to be rotated to an arrow A direction. A blade drive pin 38 is guided in a direction of approaching the optical axis, with a composed cam formed of a cam hole 32a possessed by the drive ring 32 and a cam hole 31c possessed by a base member 31. The motion amount of a circumferential direction of the blade drive pin 38 for a rotation operation angle of the drive ring 32 is small. An aperture blade 33 is moved so as to be closed by rotation of the drive ring 32, as shown in (b); and as the aperture of the aperture blade 33 becomes smaller, control sensitivity is reduced. COPYRIGHT: (C)2011,JPO&INPIT
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