| 摘要 |
PURPOSE:To obtain a recording-reproducing head which has the same recording- reproducing characteristics that a three-head type unit has, by forming a core gap of a nonmagnetic substance layer and a magnetic substance layer of low saturated magnetic flux density and high magnetic permeability. CONSTITUTION:As for recording-reproducing magnetic head A with coil 2 wound around head core 1 of high magnetic permeability and high saturated magnetic flux density such as sendust and permalloy, core gap G of width (g) (about 5mu) of contact with magnetic tape T is formed of different materials G1 and G2. Nonmagnetic substance layer G1 provides excellent reproducing characteristics. This is made of a nonmagnetic material such as glass and a titanium alloy of 0.8-1.5mu in thickness equivalent to gap width. Magnetic substance layer G2, on the other hand, is made of a magnetic material, having low saturated magnetic flux density (Br=500-4,000G) and high magnetic permeability (b=10,000-100,000), to a gap width of 3-5mu. Then, magnetic substance layer G2 is saturated with magentic flux generated by recording bias current. Thus, excellent recording characteristics can be provided in association with nonmagnetic substance layer G1. |
