| 摘要 |
A lens barrel drive unit for a camera, in which the present invention is implemented, comprises a lens barrel that is a moving object having a female screw, a drive screw that includes a male screw which engages with the female screw and that moves the lens barrel back and forth with the rotation of the male screw, a drive source for rotating the drive screw, a signal generator for generating a pulse signal according to the rotation of the drive source or drive screw, a first memory that stores a difference between a theoretical lead and an actual lead of the drive screw as a correction coefficient, a second memory that stores the theoretical number of pulses associated with a quantity of rotation of the drive screw which is required to drive the lens barrel to a given position corresponding to a subject distance, and a computing unit that uses the correction coefficient and the theoretical number of pulses to compute the actual number of pulses required for extending the lens barrel.
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