Method of driving vibration actuator with enhanced sliding efficiency, vibration drive device, and mechanical apparatus

Abstract

A method of driving a vibration actuator. The vibration actuator includes a vibration element including a piezoelectric element as an electromechanical energy conversion element and an elastic body which is joined to the piezoelectric element, and a driven element which is brought into pressure contact with the elastic body. Driving vibration is excited in the vibration element by applying a drive signal to the piezoelectric element, whereby the vibration element and the driven element are moved relative to each other. The driving vibration is vibration in which at least n-th-order vibration and 2n-th-order vibration are combined, n being a natural number.

Description

technical field [0001] The present invention relates to a method for driving a vibration actuator, a vibration driving device and a mechanical device equipped with the vibration driving device, and more particularly, to a method for increasing the sliding efficiency of a vibration actuator so as to improve the durability of the vibration actuator sex technology. Background technique [0002] The vibration actuator has such a feature that enables the vibration actuator to generate a large low-speed torque and maintain its state by friction after driving, wherein the vibration actuator makes the vibration element and the driven element press-contact each other and Vibration of the vibrating element is excited, thereby causing the vibrating element and the driven element to move relative to each other. By focusing on such features, for example, in image pickup apparatuses such as single-lens reflex cameras, vibration actuators have been put into practical use as lens drive mot...

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Problems solved by technology

[0004] However, it is difficult to say that sufficient sliding efficiency can be obtained by the technique described in Japanese Patent Laid-Open No. 2007-202227, and therefore, further improvement is required

In addition, the n-order vibration and the 3n-order vibration used in the technique described in Japanese Patent Laid-Open No. 2007-202227 have a large difference between the respective natural frequencies of the vibration, which leads to the problem that the vibration-induced Significant limitations (small degrees of freedom) exist in the mechanical design (structural design) of the actuator

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