| 摘要 |
PURPOSE:To improve the efficiency of reproduction by providing a thin ferromagnetic film, having magnetic resistance effect, as a closed magnetic path to the back surface part of a ferrite core having a gap part and by tapering it toward its center part. CONSTITUTION:So that gap part 10 is formed, L type ferrite cores 11 and 12 are provided; the gap part is filled with nonmagnetic material 13, such as glass, and thin ferromagnetic film 14, such as permalloy, having the magnetic resistance effect is provided on the back surface part of ferrite cores 11 and 12 to form a closed magnetic path. At its center part, a magnetic flux sense part is provided and in parallel to it, bias conductor 15 is provided via insulator 16 and then covered with the same insulator 16. Thin ferromagnetic film 14 forms magnetic induction part 23 decreasing in width toward the center and the center part of extremely small width is used as magnetic flux sense part 24. Fluctuations of magnetic flux at gap part 10 result in extreme fluctuations of magnetic flux density at magnetic sense part 24, which are converted into variation in magnetic resistance to flow a sense current between terminals 251 and 252, so that they are detected as fluctuations of the current. Magnetic sense part 24 has magnetic and electric congestion, so that detection having excellent reproduction efficiency is realized. |
