Structural Design and Experimental Studies of Resonant Fiber Optic Scanner Driven by Co-Fired Multilayer Piezoelectric Ceramics

Abstract

Piezo-driven resonant fiber optic scanners are gaining more and more attention due to their simple structure, weak electromagnetic radiation, and non-friction loss. Conventional piezo-driven resonant fiber optic scanners typically use quadrature piezoelectric tubes (piezo tubes) operating in 31-mode with high drive voltage and low excitation efficiency. In order to solve the abovementioned problem, a resonant fiber scanner driven by co-fired multilayer piezoelectric ceramics (CMPCs) is proposed in which four CMPCs drive a cantilevered fiber optic in the first-order bending mode to achieve efficient and fast space-filling scanning. In this paper, the cantilever beam vibration model with base displacement excitation was derived to provide a theoretical basis for the design of the fiber optic scanner. The finite element method was used to guide the dynamic design of the scanner. Finally, the dynamics characteristics and scanning trajectory of the prepared scanner prototype were tested and compared with the theoretical and simulation calculation results. Experimental results showed that the scanner can achieve three types of space-filling scanning: spiral, Lissajous, and propeller. Compared with the structure using piezo tubes, the designed scanner achieved the same scanning range with smaller axial dimensions, lower drive voltage, and higher efficiency. The scanner can achieve a free end displacement of 10 mm in both horizontal and vertical directions under a sinusoidal excitation signal of 50 V_p-p and 200 Hz. The theoretical, simulation and experimental results validate the feasibility of the proposed scanner structure and provide new ideas for the design of resonant fiber optic scanners.

Keywords: co-fired multilayer piezoelectric ceramics; dynamics characters; fiber optic scanner; finite element method; piezoelectric actuation.

Figure 3

Diagram of force analysis of cantilever beam. (a) Force analysis of beam transverse vibration. (b) Force analysis of a micro-element on the transverse vibrating beam.

Figure 1

Schematic design of the scanner. (a) Structure diagram of the scanner. (b) Distribution of the four CMPCs (yellow parts) and voltage excitation strategy for them. (c) Structure diagram of the CMPC.

Figure 2

Different scanning patterns of resonant scanners: (a) spiral scanning; (b) Lissajous scanning; (c) propeller scanning.

Figure 4

First three orders of transverse vibration displacement response curves.

Figure 5

Schematic diagram of the scanner geometry.

Figure 6

Modal analysis results of the scanner. (a) Bending vibration of the cantilever beam. (b) Two orthogonal modals (A and B) calculated by modal analysis.

Figure 7

Transient analysis results of scanner: (a) spiral scanning pattern; (b) Lissajous scanning pattern; (c) propeller scanning pattern.

Figure 8

3D vibration measuring platform.

Figure 9

Principle prototype of optic scanner driven by CMPCs.

Figure 10

Photos of four types of simple scans. (a) Linear scanning in X direction. (b) Linear scanning in Y direction. (c) Circular scanning. (d) Elliptical scanning.

Figure 11

PSD displacement response test schematic.

Figure 12

Measurement results of different scanning patterns by PSD. (a) Spiral scanning, (b) Lissajous scanning and (c) propeller scanning.

Figure 13

3D vibration measurement results.