| 摘要 |
PURPOSE:To facilitate movement with simple constitution by arranging the 1st and the 2nd rack parts for driving a zoom lens in an optical-axis direction so that both end parts are shifted mutually and moving the rack parts by a unidirectional transmission gear in the opposite directions. CONSTITUTION:When the zoom lens is moved to its wide-angle side, a driving shaft 12 is driven by a motor as shown by an arrow B and then the 1st unidirectional transmission gear 13 is driven, so that the 2nd unidirectional transmission gear 15 idles. The 1st unidirectional transmission gear 13 engages a rack part 17a to move a rack part 17 as shown by an arrow A, placing the zoom lens at its wide-angle side. When the zoom lens is further moved to the wide-angle end, the 1st unidirectional transmission gear 13 is disengaged from the 1st rack part 17a and no further movement is performed. Then, when this zoom lens device is moved from the wide-angle end to the telephoto side, the driving shaft is rotated reversely as shown by the arrow B and then the 2nd unidirectional gear 15 engages a rack member 17b to move the rack member 17 in the opposite direction from the arrow A, thereby setting the zoom lens at the telephoto side. Thus, the movement is facilitated by this simple constitution.
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