The present invention relates to a record/reproduction head applicable for a vertical magnetic recording system.
A vertical magnetic recording system, which is well adaptable for a high density recording system, has been known. The recording system employs a magnetizing pattern orthogonal to the magnetic surface of a magnetic tape as a recording medium. In harmony with the magnetizing pattern, the orientation of the magnetic material of the magnetic tape used is orthogonal to the magnetic surface of the tape. The use of such magnetizing pattern effectively reduces the demagnetization during the course of information recording. Therefore, the vertical magnetic recording system remarkably improves the frequency response, compared to an usual magnetic recording system (in-surface recording system) which employs a horizontal magnetizing pattern with respect to the magnetizing surface direction. Thus, the vertical recording system is essentially suited for high density recording, in comparison with the conventional in-surface recording system.
The above-mentioned recording system and a recording head used for the vertical magnetic recording system are disclosed in Japaness Patent Disclosure No. 134706/77. The disclosure describes that the auxiliary magnetic pole exciting type head shown in FIG. 3(c) is preferable from the view points of recording efficiency and recording density. The magnetic pole for magnetizing the magnetic medium in combination with the auxiliary magnetic pole exciting type head, that is a main magnetic pole, is made of a permalloy layer of 10 .mu.m or less in thickness. The thickness of the main magnetic pole is usually selected to be 2 to 3 .mu.m in order to magnetically-saturate the recording medium and obtain a good recording efficiency.
When the recording head is used as a reproducing head, however, it can not fully utilize the useful feature of the vertical magnetic recording system, that is, the high density recording characteristic, because the reproduction resolution (high frequency response) is poor. This follows from the fact that the reproduction resolution is restricted by the thickness of the main magnetic pole. When the effective thickness of the main magnetic pole is 3 .mu.m, for example, the information recorded on the area of the magnetic recording medium, which extends with a width of 3 .mu.m or less in the tape traveling direction, can not be reproduced. The magnetic head of the above-mentioned disclosure, which is shown in FIG. 3(c), indirectly detects by the exciting coil of the auxiliary magnetic pole a change of the magnetic flux sensed by the main magnetic pole. Therefore, the reproduction sensitivity of the head is inferior.
It is for this reason that the conventional vertical magnetic recording system employs the auxiliary magnetic pole exciting head for the recording head and the usual ring-like head for the reproduction head. The ring-like reproduction head has at most about 1 .mu.m of the effective gap width due to the restriction on the machining technique. Because of this, the conventional vertical recording system fails to fully utilize the high density recording characteristic thereof. In the case of using individually the recording head and the reproduction head for the respective purposes, the azimuth of the recording head must be coincident with that of the reproduction head. In other words, an arrangement inherently requires an azimuth adjustment. As the recording density becomes higher, the azimuth adjustment becomes more critical. This means that the azimuth adjustment is difficult for high density recording. Further, if the azimuths of the recording head and the reproduction head, when those are used, are different, the resolution of the record/reproduction is deteriorated without fail.