| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform reset operation easily and quickly after tracking is stopped by calculating a reset position, based on positional information in the past and directing a transmission light beam to the reset position after tracking is stopped. <P>SOLUTION: In order to perform automatic tracking, positional information is read out from an optical position detecting element at S11, and then a control circuit performs operation for correcting shift of the optical axis at S12. Operational results are output to a drive circuit at S13 and the direction of a transmission light beam is regulated. Subsquently, based on reset information in the past stored in a memory at S14 and newest positional information acquired at S11, newest reset position is calculated and overwritten on the memory. At S15, a decision is made whether a receiving light beam has been detected by the optical position detecting element or not and the control returns back to S11 if it has been detected before repeating the similar operation. If the receiving light beam has not been detected at S15, automatic tracking operation is ended. When automatic tracking operation is ended, the transmission light beam is emitted, based on a reset position stored in the memory. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
