| 摘要 |
PROBLEM TO BE SOLVED: To enhance the durability of the zoom finder variable power device of a camera and to smooth operation thereof. SOLUTION: A cam shaft 8 having two flange-like cam sliding surfaces 8a' and 8a", two flange-like cam sliding surfaces 8b' and 8b" and a large gear 9 is turnably axially arranged and engaged with the shaft gear 11 of a motor 10. Moving lens groups 2 and 3 are respectively fixed to holding members 12 and 13 and the bearing parts thereof 12a and 13a and interposing members 15 and 16 are slidably attached to a sliding shaft 14. The holding members 12 and 13 are prevented from being rotated by inserting the guide parts 12b and 13b thereof in the groove part 17a of a guide plate 17. Then, a torsion coil spring 18 is attached between the projection parts 12c and 13c of the holding members 12 and 13 and the projection parts 15a and 16a of the interposing members 15 and 16 in order to press them in a direction that they mutually approach so that they are respectively brought into slidable contact with the surfaces 8a', 8a", 8b' and 8b". Thus, the width of a cam moving the respective lens groups becomes almost constant in an optical axis direction. Besides, the variation of the pressing force of the spring between the holding members and the interposing members is reduced.
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