JP2611202B2 - Magnetoresistive head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a magnetoresistive head using a magnetoresistive effect used in a magnetic recording / reproducing device such as a video tape recorder, an audio tape recorder, or a digital audio tape recorder.

[Prior art and its problems]

In video tape recorders, for example, Ni-Fe, Ni
A magnetoresistive head called a cue head using a material such as -Co or In-Sb and utilizing a magnetoresistive effect is used. The track width of this cue head is usually about 1.8 mm, and the cue signal of the tape recorded on the magnetic tape is a cue signal of 30 Hz, which is included in the entire width of the magnetic tape. This signal can be sufficiently detected even when the magnetic tape runs with some fluctuation. However, considering a magneto-resistive head using the above-described magneto-resistive effect for use in reproducing an ordinary information signal, in this case, the interest is somewhat different from that of the cue head. That is, as shown in FIG. 3, a magneto-resistive head is usually formed on a glass substrate 1 by Ni-Fe, Ni-Co or In-Sb.
And the like. A magnetically responsive material such as is provided by an appropriate means such as vapor deposition, sputtering or plating, and a magnetically responsive film provided on the glass substrate 1 is etched into a predetermined pattern to form a sensor pattern 2. 2 is provided with an electrode pad 3 for external drawing at the end, and the total length (track width) of the sensor pattern 2 is set to, for example, about 5 mm. However, with such a magnetoresistive head,
When a signal having a track width of about 0.5 to 1 mm is detected, there is a drawback that the reproduction output greatly varies depending on the location of the sensor pattern 2. For example, taking the distance from the center of the sensor pattern on the horizontal axis and the magnitude of the reproduction output on the vertical axis, the graph shows the graph shown in FIG. The reproduction output is the highest, and as the distance from the center increases, the reproduction output decreases quadratically. Therefore, for example, if the magnetic tape is reproduced while fast-forwarding or high-speed rewinding without a tape guide, in this case, the magnetic tape runs while fluctuating. There are disadvantages. To solve this disadvantage, Japanese Patent Application Laid-Open No. 56-37
No. 823, JP-A-56-47921, JP-A-59-167917
In the magnetoresistive head disclosed in Japanese Patent Application Laid-Open Publication No. H10-270, when a sensor pattern formed by a magnetoresistive element connected to a pair of electrodes on a substrate is formed between a pair of supply conductors, the vicinity of the center of the sensor pattern is set to the peripheral portion near the electrodes. Although there is a technical idea to reduce the sensitivity to the magnetic field near the center by using a wider width than the periphery near the electrode, the line width of the sensor pattern is reduced by the width near the center and the periphery near the electrode. There is a problem that each must be set.

[Means to solve the problem]

The present invention has been made in view of the above problems,
A sensor pattern formed by a magnetoresistive element connected to the pair of electrodes on the substrate is formed between the pair of electrodes, and the sensitivity of the sensor pattern to a magnetic field near the center is lower than that near the electrodes. Wherein the vicinity of the center of the sensor pattern is recessed toward the pair of electrodes with respect to the periphery of the vicinity of the electrode, thereby providing a magnetoresistive head. .

【Example】

FIG. 1 is a schematic view of a first embodiment of a magnetoresistive head according to the present invention. In the figure, 1 is a glass substrate, 2 is Ni-Fe, Ni-Co or In.
-Approximately 100 to 500 formed by depositing a magnetically sensitive material such as Sb
A sensor pattern of 5 mm in total length (track width) made of a magnetic sensitive film having a thickness of 0 mm, 3 is an external lead electrode pad made of Au / Cr, Au / Ti or Co / Cr, etc. The configuration is the same as the conventional one shown in FIG. That is, in the magnetoresistive head of the present embodiment, the width of the sensor pattern 2 is fixed (20 μm), and the distance from the sliding surface of the magnetic tape, that is, the depth is 100 μm at the center 2a of the sensor pattern 2 instead. The thickness is 50 μm in the peripheral portion 2b, and linearly changed during this period. By changing the depth in this way, the sensitivity to the magnetic field at the central portion 2a of the sensor pattern 2 becomes lower than that at the peripheral portion 2b, and the magnetoresistive head having the reproducing characteristics as shown in FIG. can get. Although the shape of the sensor pattern 2 in this embodiment has been described in the case of a substantially M shape, it may be a shape such as a substantially shape or a substantially V shape.

【effect】

In the magnetoresistive head according to the present invention, a sensor pattern formed by a magnetoresistive element connected to a pair of electrodes on a substrate is formed between the pair of electrodes, and the sensor pattern is closer to a central portion than to a peripheral portion near the electrodes. In the magnetoresistive head formed so that the sensitivity to the magnetic field at the time is reduced, the vicinity of the central portion of the sensor pattern is recessed toward the pair of electrodes with respect to the peripheral portion near the electrode, so that the pair is particularly Can be connected in a pattern with almost the same line width, and a magnetoresistive element with excellent productivity can be obtained.
Furthermore, even when the magnetic recording medium is sent at a high speed for reproduction, even if the magnetic recording medium fluctuates so as to fluctuate, the reproduction output at this time is almost constant, does not fluctuate like a wave, and has a uniform reproduction output. The characteristics can be obtained, and the configuration for obtaining such characteristics only has to take into account the shape of the sensor pattern, and has a feature that it can be provided extremely easily.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a first embodiment of a magnetoresistive head according to the present invention, FIG. 2 is a graph showing the characteristics of the reproduction output of the magnetoresistive head, FIG. 3 is a schematic diagram of a conventional magnetoresistive head,
FIG. 4 is a graph showing the characteristics of the reproduction output of this magnetoresistive head. Reference numeral 1 denotes a glass substrate, 2 denotes a sensor pattern, 2a denotes a central portion, 2b denotes a peripheral portion, and 3 denotes an external lead electrode pad.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Osamu Inoue, Inventor Osamu 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi Inside (72) Inventor Naomichi 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi JVC (56) References JP-A-56-37823 (JP, A) JP-A-56-47921 (JP, A) JP-A-57-168917 (JP, A)

Claims (1)

(57) [Claims] 1. A sensor pattern formed by a magnetoresistive element connected to a pair of electrodes on a substrate is formed between the pair of electrodes, and the sensor pattern is less sensitive to a magnetic field near a center portion than at a peripheral portion near the electrodes. A magnetoresistive head formed to have reduced sensitivity, wherein a portion near the center of the sensor pattern is recessed toward the pair of electrodes with respect to a portion near an electrode.