Patent ID: 9523909
Filing Date: 2016-12-20
CPC Classification: G02B,G03B,G09G

Claim Text:
1. A resonance locking system for a Micro-Electro-Mechanical System (MEMS)-based mechanical device which uses at least one scanning micro-mirror, the system comprising: a resonance frequency sensor operative for sensing change in a varying resonance frequency of a miniature mechanical device including a moving mirror assembly having a driving frequency, by comparing a current resonance frequency to a reference; and a feedback loop changing at least one aspect of use of the miniature moving mirror assembly responsive to a current value of the resonance frequency measured by said sensor, wherein said comparing includes determining whether or not the resonance frequency is different from the driving frequency and wherein, if so, said feedback loop is used to adjust said driving frequency accordingly, wherein the system uses a PLL unit to shift the driving frequency to the resonance frequency at reference clock occurring when said apparatus for sensing crosses a zero-reference-level, wherein the mechanical device includes a stator and a rotor forming respective parallel plates of a variable capacitor and defining first and second capacitance signals, and wherein said reference comprises a zero-reference-level of a difference between said first and second capacitance signals, wherein the zero-reference-level occurs during a transition between: