Bipolar electromagnetic scanning micro lens

Abstract

The invention discloses a bipolar electromagnetic scanning micro lens which is processed by taking a silicon base material as a substrate and adopting MEMS (microelectronic mechanical system) process, and is provided with a micro reflecting mirror 2, a bipolar electromagnetic micro driver 4, a torsion beam 1, an angular transducer 3, a bipolar electromagnetic micro driver loop connection pole 5 and a supporting frame 6. According to the invention, a bipolar driving manner is adopted to drive the micro lens, so that attraction force and repulsive force are simultaneously acted on the torsion beam, and wide-angle scanning of the micro lens is realized at lower driving voltage; due to the adoption of the bipolar electromagnetic system driving structure, the response time is greatly shortened and the working frequency of the micro lens is greatly improved; and at the same time, the electromagnetic angular transducer is integrated, so that the accurate measurement of the scanning angle is realized. Therefore, the peripheral signal processing circuit of the scanning micro lens is simple and feasible, and the results of the scanning micro lens can be widely applied to the fields of medical imaging, projector spectrograph, graphic code reader and the like.

Description

technical field [0001] The invention relates to the technical field of micro-opto-electromechanical systems, in particular to a bipolar electromagnetic scanning micromirror. Background technique [0002] As one of the important devices of micro-opto-electromechanical systems (MOEMS), scanning micromirrors have been widely used in medical imaging, projectors, spectrometers and graphic code readers. The basic principle is: by precisely controlling the driving force of the mirror surface rotation, the precise control of the rotation angle of the micromirror surface is realized, so as to precisely control the propagation direction of the light. [0003] At present, most scanning micromirrors are driven by electrostatic, electromagnetic, electrothermal and piezoelectric driving principles. The traditional electromagnetic MOEMS scanning micromirror generally only has a unipolar drive, which causes the device to have disadvantages such as large volume, small rotation angle, poor s...

AI Technical Summary

Problems solved by technology

The traditional electromagnetic MOEMS scanning micromirror generally only has a unipolar drive, which causes the device to have disadvantages such as large volume, small rotation angle, poor stability, high power consumption, and short life.

Most of the electromagnetic MOEMS micromirrors that have been widely studied are driven by unipolar (attractive or repulsive force), which results in a very limited maximum deflection angle displacement of the micromirror under the condition of a certain magnetic field and current. The characteristics of the structure severely limit the wide application of electromagnetic micromirrors in the field of MOEMS, resulting in the emergence of very few mature MOEMS commercial devices that use electromagnetic drives.

If this kind of unipolar drive structure is to achieve a large deflection displacement or deflection angle, it is necessary to increase the magnetic field strength and increase the drive current, or reduce the stiffness of the beam, which will inevitably increase the system volume while improving the system drive. voltage, which severely limits its range of application

On the other hand, reducing the strength of the beam will significantly reduce the mechanical strength of the micromirror, resulting in a decrease in linearity during work and being vulnerable to impact damage

In addition, this kind of unipolar drive structure has a long response time of the device itself, so the operating frequency can only be used in a lower frequency environment, which is not suitable for applications with higher frequencies.

In addition, most of the MOEMS scanning micromirrors in the early stage need to add an additional set of external measurement system to measure their rotation angle. The whole system is bulky and the subsequent processing circuit is complicated.

These limit the application of scanning micromirrors in MOEMS

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