JP2010257499A - Magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: when recording and reproducing information on/from a thin high-performance magnetic tape by a high-speed rotation cylinder equipped with a magnetic head, an envelope is unstable, in particular, contact between the magnetic head and the thin high-performance magnetic tape at the beginning of sliding (entrance side) of the magnetic head and the magnetic tape is unstable, so that clogging and envelope deterioration hinders securement of a satisfactory error rate. <P>SOLUTION: In the magnetic head, magnetic head core half bodies having a coil window part 7 for winding a coil and joined to each other while the magnetic head core half bodies are arranged so that the end faces thereof face each other for forming a magnetic gap 3, are mounted on the cylinder recording and reproducing information to/from the magnetic tape helically. At the end of the sliding surface of the magnetic head core, a groove with a fluorine-containing hard carbon film deposited thereon is formed. The groove is deeper at the end of the sliding surface at the beginning of sliding (entrance side) than at the end of the sliding surface at the end of sliding (exit side). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a magnetic head suitable for recording and reproducing a high-frequency signal such as a device used in a high-frequency band, such as a high-vision digital VTR and a data streamer.

  In recent years, high-capacity high-definition digital VTRs, data streamers, and other systems that handle high-capacity and wide-band signals have been actively developed, and the magnetic head has a high saturation magnetic flux density that can handle these high coercive force media. Therefore, development of a magnetic head having excellent characteristics in a high frequency band of 50 MHz or more is desired in response to the narrowing of the track accompanying the increase in capacity. Further, the magnetic head has been narrowed to increase the reproduction efficiency in the high frequency band.

  Therefore, in order to meet such demands, both sides of the metal magnetic layer in which the metal magnetic film such as Sendust, amorphous magnetic alloy, FeTaN, etc. and the insulating film are laminated are sandwiched between non-magnetic substrates to improve high frequency characteristics. A so-called laminated magnetic head has been developed.

  As the nonmagnetic substrate, a ceramic material such as magnesium titanate or calcium titanate is often used. The magnetic tape, which is a magnetic recording medium, is also reduced in thickness with the increase in capacity and recording density for recording such a large amount of information. And high coercive force media such as metal vapor deposition media.

  In addition, a cylinder equipped with a magnetic head of a drive that records and reproduces a high-frequency signal or the like is also required to have a high transfer rate by increasing the rotational speed of the cylinder.

  However, in order to perform stable recording and reproduction even when the magnetic tape is thinned and the cylinder is rotated at a high speed, a good envelope is required. To that end, proposals have been made on the magnetic tape tension of the drive, the shape of the cylinder groove, the number of grooves, and the like. In the magnetic head, in order to improve and stabilize the head touch between the magnetic head and the magnetic tape, a chamfer (Patent Document 1) is provided at the end of the sliding surface of the magnetic head, or a groove is provided in the center of the sliding surface or in the longitudinal direction ( Proposals such as Patent Document 2) have been made.

JP-A-1-151019 Japanese Patent Laid-Open No. 1-235012

  However, when recording and reproducing on a magnetic tape with a high-speed rotating cylinder equipped with a magnetic head in a high-capacity, high-transfer rate drive that records and reproduces on a thin, high-performance magnetic tape (hereinafter referred to as a magnetic tape) helically, There is a problem in that the center position of the magnetic tape sliding trace of the magnetic head moves to the magnetic tape sliding end (exit side) of the magnetic head, and the envelope during recording and reproduction is not stable. Although the amount of magnetic tape sucked in is improved by the window shape, the number of grooves, and the shape of the rotating cylinder, a sufficient improvement effect cannot be obtained. In particular, there is a problem that the contact between the magnetic head at the beginning of sliding (entry side) of the magnetic tape and the magnetic tape is not stable, the envelope on the incoming side falls, and a good error rate cannot be secured. In addition, in order to improve the contact between the magnetic head and the magnetic tape, the tension of the magnetic tape is increased to cause damage to the magnetic tape in the drive running system. There is a problem that the error rate becomes poor due to clogging.

  The magnetic head of the present invention is helically mounted on a cylinder for recording / reproducing on a magnetic tape, and a magnetic head core half having a winding window around which a winding coil is wound is disposed so that the end faces thereof face each other. The magnetic head core has a groove formed by forming a fluorine-containing hard carbon film on the end of the sliding surface. It is characterized in that it is deeper at the end of the sliding surface at the beginning (entry side) than at the end of the sliding surface (outside).

  The magnetic head according to the present invention has the above-described configuration, suppresses the suction amount of the magnetic tape on the entrance side of the magnetic head in the cylinder window, is balanced with the suction amount on the exit side, and the center position of the sliding mark of the magnetic head is magnetic. This prevents the tape from moving to the exit side of the tape and makes good contact between the magnetic gap at the center of the magnetic head and the magnetic tape, and can improve the drop and instability of the envelope during recording and playback in the drive. Therefore, a good error rate can be secured. Further, it is not necessary to increase the magnetic tape tension, and the damage to the magnetic tape by the drive running system can be improved.

1 is a configuration diagram of a magnetic head in Embodiment 1 of the present invention. Slide portion and plan view of magnetic head in Embodiment 1 of the present invention The figure showing the evaluation result at the time of the recording / reproducing by the drive carrying the magnetic head in embodiment of this invention Diagram showing envelope flatness The figure showing the evaluation result at the time of continuous operation by the drive carrying the magnetic head in embodiment of this invention

  A good head touch between the magnetic head and the magnetic tape was secured, a good envelope was obtained without damage to the magnetic tape, and a drive with high capacity and high transfer rate was realized.

(Embodiment 1)
The first embodiment of the magnetic head will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of the laminated magnetic head according to the first embodiment. The laminated magnetic head includes an entry-side magnetic head core 1, an exit-side magnetic head core 2, a magnetic gap 3, a metal magnetic layer 4 that is a track formed by laminating a metal thin film and a nonmagnetic film, and a nonmagnetic substrate 5. And a glass mold 6, a winding window 7, a sliding surface exit side groove 8, and a sliding surface entrance side groove 9. FIG. 2 is a plan view of the sliding surface portion of the laminated magnetic head according to the first embodiment. In the first embodiment, an amorphous magnetic alloy Fe—Ta—N having a high saturation magnetic flux density is used for the metal magnetic film of the metal magnetic layer that is a magnetic core. The metal magnetic film may be a material containing a metal such as Si or Zn, or may be a material such as Co-based Co—Nb—Zr—Ta. The insulating film is a Si02 film, and the substrate may be a nonmagnetic Ni—Ti—Mg ceramic, or a nonmagnetic single crystal ferrite substrate. Borosilicate glass is used for the adhesive layer, and the structure of the magnetic head is a laminated magnetic head having a structure in which both ends of the metal magnetic layer 4 are sandwiched between a pair of substrates 5. The structure of the magnetic head may be a metal in gap (MIG) type or a thin film head.

  In the first embodiment, an Al203 film is formed to a thickness of 1.0 μm on a Ni—Ti—Mg ceramic substrate by known sputtering, and the magnetization easy axis directions of the pair of metal magnetic films are substantially parallel in the magnetic gap plane and the layer plane. Fe-Ta-N, which is a metal magnetic film in which the easy axis direction of magnetization other than the pair of metal magnetic films is substantially perpendicular to the magnetic gap surface, is similarly formed by sputtering to a thickness of 0.4 μm to form a nonmagnetic film A multilayer metal magnetic film in which six layers of a metal magnetic film having a thickness of 0.005 μm with a Si02 film of 8.9 μm are stacked on a multilayer metal magnetic film in which three layers of a metal magnetic layer having a thickness of 0.15 μm of an Si02 film as an insulating film are stacked. Magnetic core halves each having a track width of 1 mm are prepared, and magnetic core halves are prepared by providing grooves to be winding portions in the respective magnetic core halves. The prepared magnetic core halves are arranged so that their end faces face each other, and formed using borosilicate glass and Pyrex (registered trademark) glass so that the effective GL becomes 0.13 μm. Join the head core. A groove is formed at the end of the output magnetic head core of the bonded magnetic head at θ2 = 60 °, a groove is formed at the end of the input magnetic head core at θ1 = 30 °, and CF4 gas is used for the inner wall of each groove by the DVC method. A 1 μm fluorine-containing hard carbon film is formed. The fluorine-containing hard carbon film can be formed by a known RF method or DC method, and the introduced CF-based gas can be C2F4 gas, C2F6 gas, etc., CF-based gas and methane, butane, ethane, etc. It may be a mixture with a carbon-based gas. Using a known cylindrical grinding machine, the magnetic head core is processed with a sliding radius of curvature of 6.5 mm and cut into a magnetic head core thickness of 80 μm to prepare the magnetic head core. The magnetic head core is wound with 17 turns, and a laminated magnetic head having a gap depth of 11 μm is produced by a known tape polishing apparatus.

  In the second embodiment, a groove is formed at the end of the magnetic head core of the magnetic head at θ2 = 60 °, and a groove is formed at the end of the magnetic head core at the input side at θ1 = 45 °. Spec. As a comparative example, a magnetic head having the same specifications as in Example 1 is prepared except that no groove is provided at the end of the magnetic head core (Comparative Example 1). Further, as Comparative Example 2, a magnetic head having the same specifications as in Example 1 except that a groove is formed at the end of the outgoing magnetic head core at θ2 = 45 ° and a groove is formed at the end of the incoming magnetic head core at θ1 = 60 °. Create

  The prepared laminated magnetic head is mounted on the drive of DAT72, which is a data streamer, and 10 units are prepared for each of Embodiment 1, Embodiment 2, Comparative Example 1, and Comparative Example 2 at a high frequency of 59 MHz. The C / N, the flatness of the envelope, and the error rate at that time are evaluated.

  The result is shown in FIG. As shown in FIG. 4, the envelope flatness is obtained by envelope flatness = B / A (%) in the envelope average value A and the envelope drop amount B.

  In the result shown in FIG. 3, a groove having fluorine content is provided at the end of the magnetic head core, and the entrance end of the magnetic tape is made deeper than the exit end with respect to the groove depth. The suction amount on the side is balanced, the magnetic tape slide trace of the magnetic head is stable at the center position of the magnetic head, the magnetic gap and the magnetic tape can be in full contact, and good results are obtained without the envelope falling. It is done. Moreover, a stable envelope can be ensured by making the groove depth deeper on the entry side than on the exit side.

  Next, using the configurations of the first embodiment, the second embodiment, the first comparative example, and the second comparative example, a continuous running test is performed for 1000 hours in a high-temperature, low-humidity environment at 50 ° C. and 20%, and the envelope after 1000 hours. The results of evaluation of flatness and error rate are shown in FIG.

  In FIG. 5, even after the continuous running test, good sliding of the magnetic head and the magnetic tape can be continuously obtained, a good envelope can be secured, and a more reliable magnetic head can be obtained.

  The magnetic head according to the present invention can be applied to a device used in a high frequency band, for example, a drive for recording and reproducing a high frequency signal such as a high-definition digital VTR and a data streamer.

DESCRIPTION OF SYMBOLS 1 Entrance side magnetic head core half 2 Exit side magnetic head core half 3 Magnetic gap 4 Metal magnetic layer 5 Nonmagnetic substrate 6 Mold glass 7 Winding window 8 Outgoing magnetic head core end groove 9 Entering side magnetic head core end groove

Claims (2)

Helically mounted on a cylinder that records and plays back on magnetic tape,
A magnetic head core half having a winding window around which a winding coil is wound is disposed so that the end faces thereof are opposed to each other to form a magnetic gap, and the magnetic head core half is joined,
It has a groove formed with a fluorine-containing hard carbon film at the end of the sliding surface of the magnetic head core,
The magnetic head is characterized in that the groove is deeper at the end of the sliding surface at the beginning (entry side) than at the end of the sliding surface (outward side). The magnetic head according to claim 1, wherein the groove cutting angle of the end face on the side with the magnetic head core is 20 ° to 45 °.

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