LENS MOVING DEVICE

摘要

PURPOSE:To reduce electric power consumption and to reduce the size and weight of the device by providing a 2nd guide means which slidably and turnably holds a moving piece and a means for pinching the moving piece to the feed screw of a driving shaft. CONSTITUTION:The driving shaft 21 having the feed screw 21a is pressed and energized when a motor 20 rotates. The driving piece 18 having a notched nut 18a screwed with a small clearance slides on a 2nd guide pole 24 and moves in the optical axis direction; therefore, a lens frame 13 engaged with this driving piece 18 moves master lenses 11, 12 to focus the lenses by correctly obtaining the prescribed moving distance. The notched screw 18a screwed to the feed screw 21a has just 120 deg. contact part with the feed screw 21a in the circumferential direction and the resistance loss by the contact is decreased. The driving piece having the notched nut engaged with the lens frame is pinched to the driving shaft of the motor and the load for driving the lenses is decreased by this moving piece. The high-accuracy lens driving device which allows the use of the low-torque motor and prevents hysteresis is thus obtd.