A piezoelectric actuator with a motion-decoupling amplifier for optical disk drives

In this paper, an optical pick-up actuator is studied using a multilayered PZT (lead‐zirconate‐titanate) for possible application to slim and small-form-factor optical disk drives or mobile devices. A theoretical modeling and analysis of the PZT actuator including the dynamics of piezoelectric, electrode and substrate layers are performed to estimate the dynamic properties such as natural frequencies, resultant forces and maximum displacements. In particular, we suggest a novel stroke-amplifying structure enabling the decoupled tracking and focusing motions actuated by four parallel multimorphs. A flexure hinge mechanism is used as the displacement amplifier to extend the allowable stroke of the actuator. Experimental results using a cantilever actuator agree well with the analytical predictions. Based on the theoretical and experimental investigations, we have designed the final model of the optical pick-up actuator with a height of 2.5 mm, showing that the moving range is ±400 μm at 15 V in the focusing direction, which is appropriate for slim or small-form-factor optical disk drives. (Some figures in this article are in colour only in the electronic version)

[1]  M. Weinberg.  Working equations for piezoelectric actuators and sensors , 1999 .

[2]  J. Knittel,et al.  A swing arm actuator for a small form factor optical drive , 2009 .

[3]  Kui Yao,et al.  Design and fabrication of a high performance multilayer piezoelectric actuator with bending deformation , 1999, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[4]  T. Shrout,et al.  Ultrahigh strain and piezoelectric behavior in relaxor based ferroelectric single crystals , 1997 .

[5]  Sung Kyu Ha,et al.  ANALYSIS OF A PIEZOELECTRIC MULTIMORPH IN EXTENSIONAL AND FLEXURAL MOTIONS , 2002 .

[6]  Benno H. W. Hendriks,et al.  Highly miniaturized prototype optical drive for use in portable devices , 2003, Optical Data Storage.

[7]  Nicolae Lobontiu,et al.  Design of symmetric conic-section flexure hinges based on closed-form compliance equations , 2002 .

[8]  Seung-Yop Lee,et al.  Design of a slim-type optical pick-up actuator using PMN-PT bimorphs , 2006 .

[9]  Young-Pil Park,et al.  Swing-arm-type PZT dual actuator with fast seeking for optical disk drive , 2002 .

[10]  No-Cheol Park,et al.  Design of swing arm actuator for small and slim optical disc drives , 2007 .

[11]  Seung-Yop Lee,et al.  Theoretical modeling, experiments and optimization of piezoelectric multimorph , 2005 .

[12]  Ellad B. Tadmor,et al.  Electromechanical coupling correction for piezoelectric layered beams , 2003 .

[13]  Kyung Taek Lee,et al.  A study on optical pickup actuator for small form-factor optical disc drives , 2009 .

[14]  Roop L. Mahajan,et al.  Recent Advancements in DataPlay's Small Form-Factor Optical Disc and Drive , 2006 .

[15]  Michael Krommer,et al.  On the correction of the Bernoulli-Euler beam theory for smart piezoelectric beams , 2001 .

[16]  A. Pisano,et al.  Modeling and optimal design of piezoelectric cantilever microactuators , 1997 .

[17]  Ilhan A. Aksay,et al.  Electromechanical Behavior of PZT-Brass Unimorphs , 1999 .