Claims
- 1. For use with a perpendicular magnetic recording medium having a magnetic recording layer having an easy axis of magnetization in the direction normal tothe surface thereof, a high permeability layer backed on the rear surface of said recording layer, and a base layer supporting said recording layer and said high permeability layer, an apparatus for reproducing a signal recorded on said recording layer in the form of a perpendicular signal magnetization in the easy axis of magnetization comprising:
- a thin film of magnetic material supported by a supporting member and disposed to extend in the direction normal to the recording layer with one end of said thin film of magnetic material facing said recording layer of said magnetic recording medium at a time of the signal reproduction, a magnetic variation occurring, due to the perpendicular signal magnetization in said recording layer when said one end of said thin film of magnetic material faces said recording layer, in the part of said high permeability layer that locates in the vicinity of said one end of said thin film of magnetic material;
- a magnetically shielding member for magnetically shielding said thin film of magnetic material except said one end of thin film which is adapted for contacting said recording medium;
- a detecting coil member disposed to surround said magnetically shielding member and said thin film of magnetic material and magnetically coupled to said high permeability layer of said recording member to detect the magnetic variation occuring in said high permeability layer at the time of the signal reproduction;
- a capacitor coupled to said detecting coil member to form a resonance circuit;
- a high frequency signal source coupled to said resonance circuit for supplying a high frequency electrical signal to said resonance circurt to provide a resonance output voltage; and
- reproducing circuit means coupled to said resonance circuit for reproducing the signal recorded on said recording medium in response to a variation in the resonance output voltage of said resonance circuit coupled to said high frequency signal source, the variation in the resonance output voltage of said resonance circuit resulting from detection of the magnetic variation occuring in said high permeability layer by said detecting coil member which is magnetically coupled to said high permeability layer.
- 2. The apparatus according to claim 1, wherein said detecting coil member is formed of a thin film of a conductor.
- 3. The apparatus according to claim 1, wherein said high permeability layer is formed of Fe-Ni alloy.
- 4. The apparatus according to claim 1, wherein said recording layer is formed of cobalt-chromium layer having perpendicular magnetic anisotropy.
- 5. The apparatus according to claim 1, wherein said recording layer is formed of barium-ferrite layer having perpendicular magnetic anisotropy.
- 6. The apparatus according to claim 1, wherein said shielding member is formed of a non-magnetic conductor.
Priority Claims (1)
Number |
Date |
Country |
Kind |
58-136969 |
Jul 1983 |
JPX |
|
Parent Case Info
This application is a division of application Ser. No. 633,915, filed on July 24, 1984 now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
57-36407 |
Feb 1982 |
JPX |
57-179932 |
Nov 1982 |
JPX |
58-125219 |
Jul 1983 |
JPX |
58-125220 |
Jul 1983 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
633915 |
Jul 1984 |
|