Optical Head Using Astigmatic Micro PBS For 3.5 Inch Magneto-Optical Disk Drives

Compact-Size Optical Head For Magneto-Optical Disk Drive

10.1117/12.936836 ◽

1987 ◽

Author(s):

Teruo Fujita ◽

Nobuo Takeshita ◽

Morihiro Karaki ◽

Mitsushige Kondo ◽

Kenjiro Kime

Keyword(s):

Disk Drive ◽

Optical Disk ◽

Optical Head ◽

Optical Disk Drive ◽

Compact Size

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Dynamic Analysis of the Optical Disk Drives Equipped with an Automatic Ball Balancer with Consideration of Torsional Motions

Journal of Applied Mechanics ◽

10.1115/1.2041659 ◽

2005 ◽

Vol 72 (6) ◽

pp. 826-842 ◽

Cited By ~ 17

Author(s):

Paul C. P. Chao ◽

Cheng-Kuo Sung ◽

Chun-Chieh Wang

Keyword(s):

Multiple Scales ◽

Spindle Motor ◽

Optical Disk ◽

Torsional Stiffness ◽

Torsional Motion ◽

Disk Drives ◽

Scaled Model ◽

Supporting Plate ◽

Steady State Solutions ◽

Balanced Solution

This study is dedicated to evaluate the performance of an automatic ball-type balancer system (ABS) installed in optical disk drives (ODDs) with consideration of the relative torsional motion between the ODD case and the spindle-disk-ABS-turntable system, noting that the turntable is the supporting plate structure for disk, pickup, and spindle motor inside the ODD. To this end, a complete dynamic model of the ABS considering the torsional motion is established with assuming finite torsional stiffness of the damping washers, which provides suspension of the spindle-disk-ABS-turntable system to the ODD case. Considering the benchmark case of a pair of balancing balls in an ABS, the method of multiple scales is then applied to formulate a scaled model for finding all possible steady-state solutions of ball positions and analyzing corresponding stabilities. The results are used to predict the levels of residual vibration, with which the performance of the ABS can then be reevaluated. Numerical simulations are conducted to verify theoretical results. It is deduced from both analytical and numerical results that the spindle speed of an ODD could be operated above both primary translational and secondary torsional resonances in order to guarantee stabilization of the desired balanced solution for a substantial vibration reduction.

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