JPS60164917A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the accuracy in tracking control by driving an erasing head in the direction of swinging and tilting a magnetic tape thereby driving the magnetic tape in the transverse direction thereof. CONSTITUTION:If it is assumed that a tape 3 fluctuates in an arrow A direction during reproduction, the output reproduced by the core 8b-1 of a playback head part 8b is larger than the output reproduced by the core 8b-2 and therefore a differential amplifier 17 receiving the reproduction signals from the cores 8b-1, 8b-2 as the two inputs thereof is abled and the output from such amplifier 17 is added to a reference voltage V1 and is impressed to a piezo-electric element 13 which turns an erasing head 9 attached to a fixing plate 10 in an arrow B direction around a shaft 12 thereby varying the swing and tilt angle of the head 9 with the tape 3. The contact pressure distribution of the tape 3 with the guide 2 in the transverse direction changes. The tape 3 can move in the direction of the higher contact pressure and therefore the tape 3 moves in an arrow C direction. Said direction is where the error outputs in the outputs reproduced by the cores 8b-1, 8b-2 are made zero.

Description

DETAILED DESCRIPTION OF THE INVENTION 0) Industrial Application Field The present invention relates to a magnetic recording/reproducing device, and in particular to an auto-tracking device provided to accurately follow a signal track recorded on a magnetic tape. The present invention relates to a magnetic recording/reproducing device equipped with the following.

(B) Prior art] A compact cassette tape recorder is a magnetic recording and reproducing device for audio signals that is currently widely used, but its dynamic range is limited by the use of the highest performance tape currently available. Even if it does, it is at most about 7 QclB at 1 KHz, which is extremely narrow compared to the music source being recorded.

In view of this, the so-called PCM (Pulse CM), which samples and quantizes an audio signal and converts it into a digital signal, and records the digital signal on a magnetic tape, avoids the signal deterioration associated with magnetic recording and reproduction. Recently, a magnetic recording/reproducing method and apparatus based on code modulation (code modulation) have been proposed.

When converting analog signals such as rice and audio signals into digital signals, the amount of information increases to a level that cannot be recorded using conventional magnetic recording/reproducing devices. A method is used in which digital signals are distributed in parallel using a multi-core multi-channel fixed head.

By the way, such multi-channel fixed heads (for example,
The track width of a thin-film magnetic head is 50 to 90 μm, which is very narrow compared to the track width of a conventional analog magnetic head, so such a multi-channel magnetic head is used to record and reproduce PCM signals. Tracking control becomes important.

However, tracking control in conventional magnetic recording and reproducing devices is performed only by adjusting the attitude of the magnetic head using adjustment screws, springs, etc.
There was variation in the ln tape width direction.

This caused a lot of noise in the track and caused problems in recording and reproducing.

By the way, as an apparatus for performing tracking control, for example, one disclosed in Japanese Patent Application Laid-open No. 196653/1982 is known.

However, such devices use a U-shaped tape guide near the magnetic head to directly move the tape, which poses the problem of damaging the tape edges and impairing tracking reproducibility. .

(C) Purpose of the Invention In view of the above points, the present invention aims to provide a magnetic recording and reproducing device that can improve the accuracy of tracking control and achieve good recording and reproducing operations. Structure In order to achieve the above object, a magnetic head having a plurality of cores and capable of at least recording and reproducing signals on a magnetic tape, an erasing head for erasing signals recorded on the magnetic tape, and this magnetic head are provided. The drive means drives the erasing head in the vertical direction of the magnetic tape, and the driving means drives the erasing head in the vertical direction of the magnetic tape based on a signal reproduced from at least one core of the number of cores of the magnetic head. The configuration is such that the magnetic tape is driven in the width direction by driving the magnetic tape, thereby performing tracking control.

(E) Embodiment Figures 1 to 3 are diagrams showing an embodiment of the present invention.
is a cassette half, (2) is a tape guide provided with a cassette half ft1K, (3) is a cassette no.
), f<051 is the capstan, +61 (71 is the pinch roller, (a is for recording signals on the magnetic tape (3) or reproducing the signals recorded on the magnetic tape (3) The recording/reproducing combination magnetic head (9) is an erasing head for erasing signals recorded on the magnetic tape (3), and is of the type that is energized during erasing operation.(10) is the erasing head (9). ) is attached to the fixing plate, and is rotatably attached to the support member (II) Vc attached to the head substrate (not shown) around the shaft (12). (131 has one end attached to the fixing plate ( A piezoelectric element is attached to a mounting member (I4) whose other end is fixed to the head substrate.
9). The river is a pinch roller (6
) is a tape guide device disposed on the tape supply side (upstream) of the recording/reproducing combination magnetic head (8), and a tape guide device disposed on the tape winding side (downstream) of the recording/reproducing combination magnetic head (8).

Next, a tracking control operation in such an apparatus will be explained.

For the first time, in the present invention, as shown in FIG. core (lla-1) (8a-2)
The cores (8b-1) and (8b-2) are arranged so as to detect half of the recorded tracks, and the direction of tape fluctuation is detected based on the magnitude of the output reproduced by the cores (8b-1) and (8b-2).

That is, when the tape (3) moves in the direction of arrow A in FIG. 4 during playback, the core (
Since the playback output by the core (8b-1) is smaller than the playback output by the core (8b-2), the core (8b-1) (8b-2
), the differential amplifier (Iη becomes active, and the output of the differential amplifier θη becomes the reference voltage f
f? ) (Note that vl may be zero if the mechanical initial settings of the erasing head are reliable) VC is added and the piezoelectric element 11
4, the erasing head (9) attached to the fixed plate (10) is rotated in the direction of arrow B around the shaft (12), and the tilt angle of the erasing head (9) relative to the tape (3) is varied. (See Figure 5).

That is, the erasing head (9) uses a piezoelectric element (1:1 driving force (
zbtv/3g1t: where gl is the piezoelectric constant, t is the length, b is the width, t is the thickness, and V is the applied voltage)
direction or D direction, and the amount of displacement is 8t2v
/3g1t21! ! (However, E is Young's modulus).

When the tilt angle of the erasing head (9) with respect to the tape (3) is varied in this manner, the contact pressure distribution of the tape (3) with respect to the tape guide (2) in the width direction changes.

By the way, since the tape (3) can move in the direction of high contact pressure, for example, as mentioned above, the erasing head (9)
) in the direction of arrow B, the contact pressure at the lower end of the tape (3) increases, so the tape (3) moves in the direction of arrow C in FIG.

The movement of the tape (3) in the direction of arrow C moves the core (8b-1
) (sb-2), the tape (3) is moved by varying the tilt angle of the erasing head (9). tracking control can be achieved. Incidentally, if the tape (3) moves in the direction of arrow C and disappears, the erasing head (9) may be driven in the direction of arrow C.

Figure 6 shows another example of the servo system, in which the core (sb-
1) The error output between the reproduction output of [the core (8b-1) is arranged so as to detect half of the recording track] and the reference voltage is applied to the driving means, and the positive and negative of the error output are Detects the direction of fluctuation.

In this embodiment, a case has been described in which a piezoelectric element is used as the driving means, but the present invention is not limited to this embodiment, and for example, an electrodynamic mechanism such as a voice coil may be used.

Furthermore, the erasing head is not limited to being placed on the head substrate, but may be fixed on the mechanism chassis. Furthermore, a recording head and a reproducing head may be provided separately as magnetic heads.

(F) Effects of the Invention According to the present invention, there is provided a magnetic head having a plurality of cores and capable of reproducing at least signals recorded on a magnetic tape, and an erasing head for erasing signals recorded on a magnetic tape. and a driving means for driving the erasing head in the tilting direction of the magnetic tape, and the driving means drives the erasing head in the tilting direction of the magnetic tape based on a signal reproduced from at least one of the plurality of cores of the magnetic head. By driving the magnetic tape in the width direction, the magnetic tape is driven in the width direction, thereby performing tracking control. Therefore, the accuracy of tracking control can be improved without damaging the magnetic tape, and good playback characteristics can be achieved. can be obtained.

[Brief explanation of drawings]

Figure 3 is a diagram showing the vicinity of the erase head, Figure 4 is a diagram showing the core part of the magnetic head, Figure 5 is a block diagram showing an example of a tracking servo system, and Figure 6 is another example of a servo system. FIG. (8)...The recording head section (8a) and the playback head section (8a)
b) a recording/reproducing combination magnetic head having (9)
)... Erasing head, (+31... Piezoelectric element. Applicant: Shizuo Sano, Patent Attorney, Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 11) A magnetic head having a plurality of cores and capable of reproducing at least signals recorded on a magnetic tape, an erasing head for erasing signals recorded on the magnetic tape, and an erasing head for erasing signals recorded on the magnetic tape. a driving means for driving the head in the tilting direction of the magnetic tape, the driving means driving the erasing head to move the erasing head to the magnetic tape based on a signal reproduced from at least one core of the plurality of cores of the magnetic head; 1. A magnetic recording and reproducing apparatus characterized in that the magnetic tape is driven in the width direction by driving the magnetic tape in the tilt direction, thereby performing tracking control. (2) Claim f in which the driving means is a piezoelectric element
The magnetic recording and reproducing device according to item l).