| 摘要 |
PURPOSE:To improve erasure width accuracy by jointing a pair of magnetic core halves through a gap spacer so as to provide an erasure gap and disposing conductors on both sides in the track width direction of the gap. CONSTITUTION:A pair of magnetic core halves 1 and 2 made of Mn-Zn ferrite are jointed through a gap member made of SiO2, etc., to form the gap (g), and are machined in the vicinity of the gap (g) to regulate the prescribed track width Tw. A conductive material 6 made of Cu, etc., is coated over a pair of halves 1 and 2, and a nonmagnetic material 5 such as high melting point glass is filled. An erasure signal supply coil winding hole 4 is added to the half 2. When an erasure AC magnetic filed is impressed on the head, an eddy current is generated in the conductor 6. Accordingly, the flux leaking in the track width direction on both sides of the erasure gap (g) is canceled by the eddy current of the conductor to prevent the occurrence of an oozing magnetic field, whereby only a desired field can be erased without the deterioration of picture quality.
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