| 摘要 |
PURPOSE:To eliminate the influence of an external noise, by providing three terminals in a magneto-resistance effect element (MR element) of a magneto-resistance effect head to take out reproducing voltages differentially. CONSTITUTION:Three terminals 7, 8, and 9 for MR current supply and taking- out of reproducing outputs are provided in an MR element 6. and the terminal 9 is grounded. An MR current is supplied from terminals 7 and 8 to obtain reproducing outputs as voltages. An MR current 10 is supplied to the MR element in the side of the terminal 7 from a constant current circuit 12, and an MR current 11 is supplied to the MR element in the side of the terminal 8 from a constant current circuit 13. Since MR currents 10 and 11 have directions opposite to each other at the view from signal taking-out terminals 7 and 8, reproducing voltages appearing in terminals 7 and 8 have phases opposite to each other. Outputs appearing in terminals 7 and 8 are supplied to the + input and the - input of a differential amplifier 14, respectively and are amplified differentially to obtain a reproducing output from the MR element 6. |
