JPS6079517A - Tracking device of magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify a manufacturing process of a part containing a reproducing head and a track shift detecting head, and to execute normally an operation even in case of a large track shift by forming a control signal by comparing signal levels of both detecting heads reproduced by the detecting head provided by one piece each on both sides of plural reproducing heads, and correcting a tracking shift. CONSTITUTION:Two track shift detecting heads 11 are placed at the outermost side so as to place plural signal tracks 3 between tracks 3 between them, a signal detected by a track shift detecting head 11 is amplified by a preamplifier 12, and an output level is detected by a level detector 13. This detected output level is inputted to a differential amplifier 14, a control signal is formed by passing its output through a control signal forming device 15, inputted to an electromechanical transducing element 17, and the mechanical position of a reproducing head part 18 is displaced. In this way, a tracking shift is corrected automatically and effectively.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a tracking device for a magnetic recording and reproducing device.
For details, record signals on multiple tracks on magnetic tape. The present invention also relates to a tracking device for a magnetic recording/reproducing device for reproducing signals.

[Technical background of the invention and its problems]

In a multi-track magnetic recording/reproducing device, it is necessary to record many tracks within a narrow tape width, so it is necessary to reduce the width of one track. Therefore, tracking during playback greatly affects the quality of the playback signal. Particularly recently, technology has been developed to record and play back audio signals using PCM on compact cassettes7.
,in this case.

Since it is necessary to record 20 to 40) racks within a tape width of 3.8 nm, the width of one track is approximately 50 to 100 μm, and in order to ensure the quality of the reproduced signal, there is no limit to tracking deviation. It's becoming very difficult.

Conventionally, as a countermeasure against this problem, several devices have been devised to perform over-tracking by detecting the track deviation and moving the playback head based on the detected track deviation.

FIG. 1 is a diagram for explaining a track deviation detection method of a conventional auto-tracking device.

Here, (1) is a magnetic tape, and (2) is a recording head.

A plurality of these are arranged on a straight line. Also (3). (5) is a track deviation detection head, and these two detection heads (5) and (5) detect track deviation. That is, when the head (2) records a signal, the head (6) simultaneously records a predetermined signal on the track (7) dedicated to track deviation detection, and during playback, the two track deviation detection heads (5) and (51) This detects track deviation. Based on this detection output, the position of the reproducing head group is changed to eliminate the track deviation.

In this case, the magnetic tape (1) is provided with a track (7) dedicated to detecting track deviation in addition to the signal track (3).
A dedicated recording head (6) is required. When using the track (7) dedicated to track misalignment detection, the width that can be used for recording and playback on the magnetic tape (1) is limited (magnetic tape (
There is a phenomenon in which the output decreases as it approaches the end face in the width direction of 1), and the 8/N ratio worsens, so this part cannot be used for recording and reproduction) 6 Therefore, it is necessary to reduce the width of the signal track (3) accordingly. There is a problem that if the width of the signal track (3) is narrowed, the output will decrease and the S//N will deteriorate, which is disadvantageous.

FIG. 2 is a diagram for explaining another example of the conventional track deviation detection method. In this case, the dedicated track (7) for track deviation detection is not required, but since the track deviation detection head (5) is placed adjacent to the playback head (4) that plays back the signal track (3), the playback head (4
) and the track deviation detection head (5), the manufacturing process becomes complicated.

In addition, in the case of the track deviation detection method shown in FIGS. 1 and 2, track deviation can only be detected in about half of the track width, so the auto-docking operation is also about half of the track width.

If the track deviation is larger than that, a malfunction will occur. Therefore, in the case of these methods, it is necessary that the basic mechanical precision of the tape running system (tape waving) be within about half of the track width, and the mechanical design of the tape running system must be Conditions become stricter.

Furthermore, even if the waving of the tape is within the permissible value under normal running conditions, when an impact is applied, the track deviation may temporarily exceed half the track width, which is a major practical problem. It was humming.

[Purpose of the invention]

The present invention has been made in view of the above, and is a magnetic recording/reproducing device in which a plurality of tracks are formed in the width direction of a tape, which does not require a dedicated track for detecting track deviation, and can be used in a portion including a playback head and a track deviation detection head. It is an object of the present invention to provide a tracking device for a magnetic recording/reproducing device which has a simple manufacturing process, has a wide track deviation detection range, operates normally even in the case of a large track deviation, and is extremely effective in practice.

[Summary of the invention]

This invention comprises a multi-track magnetic recording/reproducing device in which a plurality of recording heads and a plurality of reproducing heads are arranged in a straight line, and when a track recorded by the recording head is reproduced by the reproducing head, 1) racking is performed. A head for detecting the deviation is provided on each side of the plurality of playback heads (playback head group), and the levels of the two signals played back by the detection heads are compared, and based on the compared signals. The control signal is used to drive a head moving means provided in the reproducing head to displace the mechanical position of the reproducing head, thereby effectively correcting the tracking deviation.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a diagram showing a track deviation detection portion in an embodiment of the tracking device of the magnetic recording/reproducing apparatus according to the present invention. (1) is a magnetic tape, (2) is a recording head, (
3) is a signal track, (4) is a reproducing head, and ▪ is a track deviation detection head.

The configuration of this embodiment includes two track deviation detection heads CL.
1) is placed on the outermost side so as to sandwich a plurality of signal tracks (, 3). In other words, the playback head group ((4)
, (4),...) have track misalignment detection heads on both sides.

αυ is established.

In the configuration shown in FIG. 3, the track deviation detection signals detected by the trunk deviation detection heads U and Ut+ are processed according to the block diagram of FIG. 4, and the track deviation is completely automatically corrected.

That is, the signal detected by the track deviation detection head 11) is amplified by the preamplifier.

The output level is detected by a level detector 03). Input this detected output level to the differential amplifier (14),
Its output is controlled by the control signal former a! 9, a control signal is generated and inputted to the drowsiness-to-mechanical conversion element αD through an amplifier 116), thereby displacing the mechanical position of the reproduction head. This effectively and automatically corrects tracking deviation.

According to the magnetic recording/reproducing apparatus of this embodiment, detection of drag deviation is not limited to less than half the track width;
The wider the track deviation detection head (11), the wider the range of track deviation detection. The recording head (2) used here may be either a conventional bulk head or a thin film magnetic head, and the reproducing head (4) and track deviation detection head α1) may be a conventional bulk head, thin film magnetic head, or magnetoresistive element. Any MR head using the above may be used.

In addition, the electro-mechanical conversion elements used here include those that use a movable coil (voice coil), those that use a piezoelectric effect, and those that can generate five mechanical qualities by adding electrical input such as a motor. Any one is fine as long as it is in a hermitage.

In the above embodiment, the playback head and the track deviation detection head are arranged in a straight line, but if the manufacturing process is allowed to be slightly complicated, the playback head and the track deviation detection head can be arranged as necessary. A similar effect can be achieved even if the tape is shifted back and forth in the longitudinal direction of the tape.

[Effects of the Invention] As described above, according to the magnetic recording/reproduction-A arrangement according to the present invention, there is no need for a dedicated track for detecting track deviation, and the width of the signal track can be increased accordingly, and the b/ N improves. In addition, since the playback head and the track deviation detection head can be arranged in a straight line,
The manufacturing process for the portion including the reproducing head and the track deviation detection head is simple.

This is the most remarkable effect, but the detection range for track deviation is wide, and it operates normally even when a small track deviation occurs due to impact, etc., and is extremely effective in practice. Furthermore, when this auto-tracking device is used, the mechanical precision required in the tape running system is greatly reduced, contributing to a reduction in the cost of the entire system.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the track deviation detection method of a conventional auto-tracking device, FIG. 2 is a diagram for explaining another conventional track deviation detection method, and FIG. 3 is a diagram for explaining the magnetic recording according to the present invention. FIG. 4 is a diagram showing an embodiment of a track deviation detection section of a tracking device of a playback device, and FIG. 4 is a block diagram showing an embodiment of the tracking device of the present invention. 1...Magnetic tape. 2... Recording head. 4...Playback head. 11...Track deviation detection head. 14... Comparator. 15...Control signal former. 17...Electro-mechanical conversion element. 18... Playback head section. Agent Patent attorney Kensuke Norichika (and 1 other person) Figure 1 Figure 2 Figure 3m Figure 4

Claims (1)

[Claims] Multi-track signal recording is performed by a recording head group consisting of a plurality of recording heads arranged linearly in the width direction of a running magnetic tape, and a plurality of playback heads arranged linearly in the width direction of the tape. A tracking device for a magnetic recording and reproducing apparatus that performs reproduction using a reproducing head group consisting of a head moving means for moving the regenerative head group in the width direction of the tape, and a tracking deviation detection means provided on both sides of the reproducing head group. The apparatus comprises two heads, a comparator for comparing output levels of reproduction signals obtained from these two heads, and means for forming a trunking control signal for the reproduction head group based on the output signal from the comparator. A tracking device for a magnetic recording/reproducing apparatus, characterized in that a head moving means is driven by the output of the control signal forming means.