Flying Height Control with Quadrant Detector Measurement in Near-Field Optical Disk Drives

• Main Authors: Chuan-Yu Peng, 彭釧瑜
• Other Authors: Tzong-Shi Liu
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/69625041935488271651

碩士 === 國立交通大學 === 機械工程系所 === 93 === To realize near-field optics and hence increase storage capacity and density in near-field optical disk drives, the flying pickup head has to enable the slider to fly at a stable height above the disk surface. Since both the precision of track pitch and the flying height reach nanoscale, it remains to increase the motion accuracy of a pickup head. In this study, a PZT bender is used as an actuator of the pickup head while quadrant photodetectors are used as sensors. Based on an optical lever method and addition-and-subtraction operations in op-amp circuits, the relative position variation between a disk and a pickup head is measured. This study designs a sliding mode controller inherited with robust properties to deal with model uncertainty and external disturbances, so as to maintain stable flying height.