JP2777424B2 - Magnetic recording / reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing device such as a DAT (Digital Audio Tape Recorder), and more particularly to a magnetic recording / reproducing device capable of reproducing a stable signal. It is.

[Conventional technology]

As a rotary head for recording and reproducing signals on a magnetic tape of such a magnetic recording and reproducing apparatus, for example, FIG.
There is a head drum shown in the figure. In the figure, 1 is “+”
An azimuth recording head, 2 is a "-" azimuth recording head facing the recording head 1, 3 is a "+" azimuth reproducing head for reproducing a signal recorded by the recording head 1, and 4 is recorded by the recording head 2. A "-" azimuth reproducing head, which reproduces a signal and faces the reproducing head 3, has a recording head 1,
2 is a cylinder / drum on which the reproducing heads 3 and 4 are mounted.

Further, as shown in FIG. 3 (b), the reproducing heads 3, 4 and the recording heads 1, 2 are respectively mounted on the same plane, but the mounting surfaces of the reproducing heads 3, 4 and the recording heads 1, 2 are mounted. There is a step between the surface and the lead, after,
At the time of writing (checking the recording state with the reproducing head after recording), the recording track is set to scan at the position where the reproducing heads 3 and 4 are on-track. The head width of the recording heads 1 and 2 and the reproducing heads 3 and 4 is generally set to approximately 1.5 times the track width (abbreviation: TP).

Next, the operation will be described with reference to FIGS. First, at the time of recording, when performing so-called read-after-write for the purpose of monitoring a recording signal, recording of "+" azimuth is performed by the recording head 1, and "+" azimuth reproducing head 3 is almost simultaneously with the end of recording. Recording head 1
The recorded signal is monitored by the recording head 1 by tracing the track recorded by the above and reproducing the signal.

Next, at the time of reproduction, the reproduction heads 3 and 4 function to perform tracking in the ATF area and signal reproduction in the sub data area and the main data area as shown in FIG. That is, since the reproducing heads 3 and 4 are made with a track width almost 1.5 times as large as the specified track width, when passing over the ATF track, signals should be picked up even if the position is slightly shifted from the track center. The crosstalk of the ATF signals from the adjacent tracks is detected, and the tape feed speed of the capstan (not shown) is controlled so that the left and right crosstalk amounts are equal. The center is centered on the track.

[Problems to be solved by the invention]

In the magnetic recording / reproducing apparatus described above, ATF tracking and sub data and main data signal reproduction are both performed by reproduction-only (including a read-after-write monitor) heads 3 and 4 during reproduction. Therefore, the head width is more advantageous for error elements such as track bending, but the head width is made too large to prevent occurrence of malfunction due to picking up an ATF signal from an adjacent track. Can not be 1.5
Is a practical limit, so tracking and tracking
There has been a problem that an RF output level is reduced due to an error.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has been made in consideration of the sub data
It is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of increasing a margin of tracking for an area and a main data area and obtaining a stable reproduction signal.

[Means for Solving the Problems] In order to achieve the above object, a magnetic recording / reproducing apparatus according to the present invention includes a magnetic recording / reproducing apparatus in which recording and reproduction of a signal is performed by a rotary head.
A plurality of sets of two magnetic heads mounted diagonally in degrees are provided as one set, the width of a pair of read heads constituting one set of the plurality of sets is larger than the width of the other pair of magnetic heads, and At least 1.5 times the recording track pitch, tracking is performed by a magnetic head other than the reproducing head during reproduction, and the reproducing head is composed of a sub data area and a main data area.
The configuration is such that only the reproduction of the area is performed.

(Operation)

According to the magnetic recording / reproducing apparatus of the present invention, the head width of a pair of magnetic heads used exclusively for reproduction selected from a plurality of sets of magnetic heads is larger than the width of another pair of magnetic heads, and the recording track pitch is smaller. 1.5 times or more, at the time of reproduction, the sub data and main data are reproduced using the wide head dedicated to the reproduction, while the ATF tracking is performed by another magnetic head, so the tracking margin is increased and stable Obtain a playback signal.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same parts as those in the above-described conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a block diagram showing an embodiment of the present invention. 1 and 2 are "+" and "-" respectively.
It is an azimuth recording head, and the head width is almost 1.5 TP as before. Reference numerals 3 and 4 are "+" and "-" azimuth reproducing heads, respectively. The head width is 1.5 TP.
This is set as above. Reference numeral 6 denotes a changeover switch for using the recording heads 1 and 2 as a reproducing head during reproduction.
Is a recording amplifier, 8 is a digital signal processing circuit for recording,
Reference numeral 9 denotes an input end of a recording data signal.

10 is a changeover switch 6 for reproducing the recording heads 1 and 2
Is a reproduction amplifier that amplifies a reproduction signal when operated as a reproduction head by switching between them, an ATF processing circuit 11 that processes an ATF signal to obtain a tracking signal, and 12 is an output terminal of the ATF tracking signal.

Reference numeral 13 denotes a reproduction amplifier for amplifying reproduction signals from the reproduction heads 3 and 4, reference numeral 14 denotes a digital signal processing circuit during reproduction, and reference numeral 15 denotes a reproduction data signal output terminal.

The operation of the above configuration will be described with reference to FIG. First, at the time of recording, recording data is supplied from a digital processing unit (not shown) (for example, an A / D converter or a data buffer memory) to the input terminal 9, and the digital signal processing circuit 8 performs error correction according to the DAT format. Signal addition and interleaving are performed, and further subjected to 8-10 modulation and output to the recording amplifier 7. The recording amplifier 7 outputs a logic level recording signal from the digital signal processing circuit 8 to the recording heads 1 and 2.
And amplifies it into a recordable voltage / current and supplies it via a changeover switch 6. After recording on the magnetic tape by the above series of operations, a check by read-after-write is performed.

That is, the signal recorded by the recording head 1 is
, And the signal is immediately amplified by the reproduction amplifier 13 to the logic level. Then, the digital signal processing circuit 14
, 8-10 demodulation, de-interleaving and error detection processing are performed to check the quality of the recording signal. When it is determined that the quality has not reached the preset level, a predetermined process such as re-recording is performed.

Next, at the time of reproduction, an ATF signal is detected by switching the changeover switch 6 to operate the recording heads 1 and 2 as a reproduction head, amplified by the reproduction amplifier 10 through the changeover switch 6, and then processed by the ATF processing circuit 11. To generate a signal necessary for tracking and output the signal to the output terminal 12.

In this case, as shown in FIG. 2, the recording head 1 (functioning as a reproducing head) performs tracking with an offset applied so that the center of the reproducing head 3 traces the center of the recording track. In addition, reproduction head 3,4
The reproduction output from is amplified by a reproduction amplifier 13, subjected to 8-10 demodulation, de-interleaving and error detection / correction by a digital signal processing circuit 14, and output to an output terminal 15 as a reproduction data signal.

〔The invention's effect〕

As described above, according to the present invention, of a plurality of magnetic heads attached to a rotating drum, the head width of a pair of magnetic heads used exclusively for reproduction is larger than the width of another pair of magnetic heads, and Since the read-only head is used only for reproducing the sub data area and the main data area, and the ATF tracking is performed by another magnetic head, the tracking RF output level drop due to errors can be prevented,
A stable reproduction signal can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus of the present invention, FIG. 2 is a track trace diagram of the same rotary head, and FIG. 3 is a head configuration diagram of a conventional magnetic recording / reproducing apparatus.
4A is a plan view, FIG. 4B is a front view, FIG. 4 is a track trace diagram of the rotary head, and FIG. 5 is a head trace diagram of one track by the rotary head. 1 ... "+" azimuth recording head, 2 ... "-" azimuth recording head, 3 ... "+" azimuth reproducing head, 4 ...
... "-" azimuth reproducing head, 6 ... changeover switch, 7
…… Recording amplifier, 8 …… Digital signal processing circuit (for recording), 10,13 …… Reproduction amplifier, 11 …… ATF processing circuit, 14…
... Digital signal processing circuit (for reproduction)

Claims (2)

(57) [Claims] 1. A magnetic recording / reproducing apparatus in which recording and reproduction of signals are performed by a rotary head, wherein a plurality of sets of two magnetic heads mounted on a rotary drum at a diagonal of 180 degrees are provided as one set. The width of one pair of read heads constituting one set is larger than the width of the other pair of magnetic heads and is at least 1.5 times the recording track pitch, and the tracking is performed by a magnetic head other than the read head during reproduction. And a reproducing head for reproducing only the sub data area and the main data area. 2. The recording head according to claim 1, wherein said pair of magnetic heads comprises a read head and said other pair of magnetic heads.
2. The magnetic recording / reproducing apparatus according to claim 1, wherein tracking is performed using said recording head during reproduction.