Structure for sensing motion track of voice coil motor

Abstract

The invention discloses a structure for sensing the motion track of a voice coil motor. The voice coil motor at least includes a yoke plate, an upper cover, a coil, a driving magnet, a bracket, and a base. The voice coil motor also includes a The circuit board on the inner wall of the board, the circuit board includes a PET circuit board and an injection molding board for fixing the PET circuit board, the PET circuit board is provided with a Hall IC chip and a capacitor connected in parallel with the Hall IC chip, and the bracket corresponds to the Hall IC chip. One side of the Hall IC chip is provided with a feedback magnet matched with the Hall IC chip, the coil is wound outside the bracket, and the driving magnet is arranged on the outer periphery of the coil without interfering with the feedback magnet. The driving magnet and the coil play the role of driving the vertical movement of the lens set in the bracket to adjust the focal length, and the feedback magnet and Hall IC chip play the role of negative feedback to adjust the current of the input coil, so that the movement track of the bracket and the lens is more accurate. precise. The invention has low cost and stable performance.

Description

technical field [0001] The invention relates to a voice coil motor, in particular to a structure for sensing the movement track of the voice coil motor. Background technique [0002] Nowadays, with the development of science and technology, digital devices with photographing and video recording functions are widely used, and the above-mentioned devices usually have the function of adjusting the focal length. [0003] An existing closed-loop voice coil motor drives the lens through the interaction between the coil and the magnetic field generated by the magnet, so that the lens can move in the vertical direction, thereby realizing the focal length adjustment function of the lens, and the coil is fixed, and the magnet is dynamic. , the magnetic field strength at different points in the vertical direction will change when the magnet moves vertically, the change of the magnetic field strength is sensed by the fixed and interconnected PCB board and the Hall element, and the feedb...

AI Technical Summary

Problems solved by technology

[0004] However, because the above-mentioned closed-loop voice coil motor is dynamic, it is not only a driving magnet, but also a feedback magnet. In this way, the magnetic field generated by the current in the Hall element will affect the magnetic field of the driving magnet, and the distance between the driving magnet and the Hall element will be too large. Factors such as the influence caused by the distance will cause errors in both the drive and feedback processes

Furthermore, the circuit board of the existing voice coil motor is designed by using the FPC circuit board, which has complicated process and high processing cost

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