| 摘要 |
PURPOSE:To adjust the relative position of a head on a disk surface to a normal position under self-control by the simple constitution that the reflected luminous flux of laser beam incident to the disk recording surface at constant incident angle (theta) is led to a photoelectric converter divided into four sections via a different optical path from the incident luminous flux. CONSTITUTION:Container 11 constituting optical data reading and writing device HD (head) has an opening tip; light source holding base 4 holding spot light source 5 and photodetection parts holding base 6 holding photoelectric converter 7 in the interior are incorporated on optical axes Z1 and Z3, respectively, and lenses L1, L3 and L2 are placed on optical axes Z1 and Z3, and optical axis Z2 of head HD. Photoelectric converter 7 is electrically divided into four parts (alpha), (beta), (gamma), and (delta) by split planes 9 and 10; a luminous flux from spot light source 5 is made incident to the disk recording surface and its reflected light is photodetected by photoelectric converter 7, which leads four output signals out of the head to arithmetic circuit SC, thereby outputtting three kind of arithmetic outputs. |
