Document Type and Number:
Japanese Patent JPS6231510
Kind Code:
B2
Abstract:
PURPOSE:To perform tracking free from the effect of residual distortions by applying the AC voltage of specified amplitude upon completion of position correction to an electro-mechanical transducer such as bimorph piezoelectric element or the like for head position correction. CONSTITUTION:The electric field of a specified direction through the adder 17, drive circuit 18 of an oscillator 16 is applied to the piezoelectric element 19 of bimorph plate according to the feedback signal of the level corresponding to the tracking position of a head 19 through a synchronous detection circuit 23, whereby the head 19 is corrected to the tracking position. When the connection of a switch 14 is changed over after the completion of this correction, the electric field 0.25 to 0.75 times the anti-electric field E at the magnetic erasing rate 100% of the element 19 is applied from an attenuation AC signal generator 32 to the element 19 via circuit 18, thus the tracking of the head 20 is accomplished via the element 19 in the state where there are virtually no residual distortions. As a result, the good tracking free from the effect of the residual distortions of the piezoelectric element, etc. is performed.
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Inventors:
KUBOTA YUKIO
NOMICHI KEIKO
WATANABE YOSHIMI
NOMICHI KEIKO
WATANABE YOSHIMI
Application Number:
JP3500278A
Publication Date:
July 08, 1987
Filing Date:
March 27, 1978
Export Citation:
Assignee:
SONY CORP
International Classes:
H04N5/783; G11B5/58; G11B5/592; H01L41/09