Closed-loop voice coil motor based on capacitance ranging principle and driving method thereof

Abstract

The invention relates to a closed-loop voice coil motor based on a capacitance ranging principle and a driving method thereof.The closed-loop voice coil motor comprises a protective shell, a base, a lens carrier, an elastic piece assembly, a driving assembly, a metal material belt set and a closed-loop control assembly, the driving assembly comprises a coil and a magnet, and the elastic piece assembly comprises an upper elastic piece and a lower elastic piece; the technical key points are that the closed-loop control assembly comprises a detection metal terminal I arranged on the lower elastic sheet and a detection metal terminal II corresponding to the detection metal terminal I. The detection metal terminal II is fixed on an independent metal material belt I in the metal material belt group. The detection metal terminal I and the detection metal terminal II are arranged at intervals along the optical axis direction of the lens and have projection overlapping surfaces. According to the invention, the problem that the thrust of a carrier is restricted due to the adoption of a matching structure of a Hall sensing element, a magnet and a coil in the existing voice coil motor is solved, the internal space is saved, and compared with the existing voice coil motor, the thrust is increased under the same volume, and the focusing and focusing compensation effects are enhanced at the same time.

Description

technical field [0001] The invention relates to the technical field of voice coil motors, in particular to a closed-loop voice coil motor based on the principle of capacitance ranging and a driving method thereof, which are suitable for driving optical elements such as lenses to realize focusing and focusing functions. Background technique [0002] Because the Voice Coil Motor (VCM) has the advantages of simple structure, small size, low energy consumption, no noise, high acceleration, fast response speed, accurate displacement and low price, it is currently used for camera autofocus devices. The autofocus function of the voice coil motor is still the most cost-effective solution. By fixing the optical lens on the voice coil motor carrier, the carrier acts as a power unit for the movement of the lens, and connects the voice coil motor carrier and the stator part through a reed. When the motor is powered on, the carrier will move linearly along the optical axis of the lens, t...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a closed-loop voice coil motor and its driving method based on the principle of capacitive distance measurement with a more reasonable structure and more reliable use, so as to solve the problem of using Hall sensor elements, magnets and coils in existing voice coil motors. The matching structure leads to the problem that the thrust of the carrier is restricted, which saves the internal space. Compared with the existing voice coil motor, the thrust of the same volume is increased, and the focus and focus compensation effect are enhanced at the same time.

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