JPH03125302A - Magnetic decording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a stable reproducing signal by setting the head width of a set of magnetic heads which is only used for reproducing among plural sets of magnetic heads attached to a rotating drum so that it may be 1.5 or more times as wide as the width of a track. CONSTITUTION:By switching a changeover switch 6 and making recording heads 1 and 2 act as a reproducing head at the time of reproducing, an ATF signal is detected and amplified by a reproducing amplifier 10 through the changeover switch 6. Then it is supplied to an ATF processing circuit 11 to generate a signal required for tracking, which is outputted to an output end 12. In such a case, the recording head 1 performs tracking in an offset state so that the center of the reproducing head 3 may trace the center of a recording track. The reproducing output from the reproducing heads 3 and 4 is amplified by a reproducing amplifier 13, and it is 8-10 demodulated and the error thereof is detected and corrected with de-interleave in a digital signal processing circuit 14, then it is outputted to an output terminal 15 as a reproduced data signal.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device such as a DAT (digital audio tape recorder), and particularly to a magnetic recording and reproducing device that is capable of reproducing stable signals. It is.

[Conventional technology]

An example of a rotary head for recording and reproducing signals on a magnetic tape in such a magnetic recording and reproducing apparatus is the head drum shown in FIG. 3(A). In the figure, 1 is a recording head with a "+" azimuth, and 2 is a recording head with a "-" azimuth opposite to the recording head l.
``Azimuth recording head'' 3 is a ``+'' azimuth playback head that plays back the signal recorded by the recording head 1; 4 is a ``-'' azimuth playback head that plays back the signal recorded by the recording head 2 and faces the playback head 3. Head, 5 is recording head 1.2
and a cylinder drum on which reproducing heads 3 and 4 are mounted.

Furthermore, as shown in FIG. 3(b), the reproducing heads 3.4 and the recording heads 1, 2 are each mounted on the same plane, but the reproducing heads 3, 4 are mounted on the surface and the recording head 1.
．． For mounting 2, there is a step between the surface and the lead.
At the time of after-writing (confirming the recording state with the playback head after recording), the playback head 3 and 4 are set to scan the recorded track at an on-track position. In addition, the head width of the recording heads 1, 2 and the reproducing heads 3, 4 is generally the track width (abbreviation: TP).
It is set to approximately 1.5 times.

Next, the operation will be explained with reference to FIGS. 4 and 5.

First, when performing so-called read-after-write for the purpose of monitoring recording signals during recording, the recording head 1
"+" azimuth recording is performed, and almost at the same time as the recording ends, the "+" azimuth playback head 3 traces the track recorded by the recording head 1 and reproduces the signal, thereby reproducing the signal recorded by the recording head 1. Monitor.

Next, during reproduction, the reproduction heads 3 and 4 function to perform tracking in the ATF 61 area and signal reproduction in the sub data area and main data area, as shown in FIG. That is, since the playback heads 3 and 4 are made with a track width that is approximately 1.5 times the specified track width, when passing over the ATF rank, the signal will not be processed even if the position is slightly off from the track center. can be picked up,
The crosstalk of ATF signals from adjacent tracks on both sides is detected, and the tape feed speed of the capstan (not shown) is controlled so that the amount of crosstalk on the left and right sides is equal, so that the center of the playback heads 3 and 4 is always aligned with the track. I try to keep it centered.

[Problem to be solved by the invention]

By the way, in the magnetic recording and reproducing apparatus described above, during reproduction, both the ATF (ATF) rough king and signal reproduction of sub data and main data are performed by the reproduction-only heads 3 and 4 (including monitor during read/after write). Because we are doing
The wider the head width is, the more advantageous it is in dealing with error factors such as trunk bending, but on the other hand, the head width cannot be made too wide in order to prevent malfunctions caused by picking up ATF signals from adjacent tracks. The practical limit is about 1.5 times the trunk width, and this causes a problem in that the RF specific output level decreases due to tracking errors.

The present invention has been made in order to solve the above-mentioned conventional problems, and increases the margin of tracking for the sub data area and main data area during playback, and provides a stable playback signal. The object of the present invention is to provide a magnetic recording/reproducing device that can be obtained.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a magnetic recording and reproducing apparatus in which signals are recorded and reproduced using a rotating head.
At least two or more sets are provided, each consisting of two magnetic heads mounted diagonally on each other, and the width of a pair of reproducing heads constituting one of the plurality of sets is equal to one recording track pitch.
．． 5 times or more, and during reproduction, tracking is performed by a magnetic head other than the reproducing head, and the reproducing head is configured to perform reproduction only of the sub data area and the main data area.

[For production]

In the magnetic recording and 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 set to be 1.5 times or more the track width. reproduces the sub data and main data using a wide head dedicated to this reproduction, while ATF)
Since racking is performed using another magnetic head, tracking margin is increased and a stable reproduction signal is obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. The same parts as in the above conventional example are given the same reference numerals and detailed explanations will be omitted. FIG. 1 is a block diagram showing an embodiment of the present invention. 1 and 2 are recording heads of "+" and "-" azimuth, respectively, and the head width is approximately 1.5 TP as in the conventional case. 3 and 4 are playback heads of "+" and "-" azimuth, respectively, and the head width is 1.
It should be set to 57P or higher. 6 is a changeover switch for using the recording heads 1 and 2 as a reproduction head during reproduction; 7 is a recording amplifier; 8 is a digital signal processing circuit during recording; and 9 is an input terminal for recording data signals.

10 is a reproduction amplifier that amplifies the reproduction signal when the recording heads 1 and 2 are operated as a reproduction head by switching the changeover switch 6 during reproduction; 11 is an ATF processing circuit that processes the ATF signal and obtains a tracking signal; 12 is the output terminal of the ATF tracking signal.

13 is a reproduction amplifier that amplifies the reproduction signal from the reproduction hoods 3 and 4; 14 is a digital signal processing circuit during reproduction; 15
is the output end of the reproduced data signal.

The operation of the above configuration will be explained with reference to FIG. First, during recording, recording data is supplied to the input end 9 from a digital processing section (for example, an A/D converter or a data buffer memory, etc.) not shown;
The digital signal processing circuit 8 performs signal addition and interleaving for error correction according to the DAT formant, and further performs 8-10 modulation and outputs the signal to the recording amplifier 7. The recording amplifier 7 sends the logic level recording signal from the digital signal processing circuit 8 to the recording head 1.
2, the voltage and current are amplified to recordable voltage and current, and the voltage and current are supplied via the changeover switch 6. After recording is performed on the magnetic tape through the series of operations described above, a check is performed by read-after-write.

That is, a signal recorded by the recording head 1 is immediately reproduced by the reproduction head 3, and amplified by the reproduction amplifier 13 to a logic level. After that, the digital signal processing circuit 1
At step 4, 8-10 demodulation, deinterleaving, 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,
Predetermined processing such as recording again is performed.

Next, during playback, the ATF signal is detected by switching the changeover switch 6 to operate the recording heads 1 and 2 as a playback head, amplified by the playback amplifier 10 via the changeover switch 6, and then amplified by the ATF processing circuit 11. It generates a signal necessary for tracking and outputs it to the output terminal 12.

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

〔Effect of the invention〕

As described above, according to the present invention, the head width of the pair of magnetic heads used exclusively for reproduction among the plurality of sets of magnetic heads attached to the rotating drum is set to be at least 1.5 times the trunk width. The read-only head is used only for reproducing the sub-data area and main data area, and roughking (ATF) is performed using another magnetic head, which reduces the possibility of high RF output due to tracking errors. Level drop can be prevented and stable reproduction signals can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the magnetic recording/reproducing device of the present invention, FIG. 2 is a track trace diagram of the rotary head, and FIG. 3 is a head configuration diagram of a conventional magnetic recording/reproducing device.
(A) is a plan view, (B) is a front view, FIG. 4 is a trunk trace diagram using the same rotating head, and FIG. 5 is a head trace diagram per track using the same rotating head. 1... "+" azimuth recording head, 2... -" azimuth recording head, 3... "+" azimuth playback head, 4... "-" azimuth playback head, 6... changeover switch, 7... Recording amplifier, 8... Digital signal processing circuit (for recording), 10.13... Playback amplifier, 1
1...ATF processing circuit, 14...Digital signal processing circuit (for reproduction) Fig. 2 (d) (0) Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] In a magnetic recording and reproducing device in which signals are recorded and reproduced by a rotating head, at least two sets of two magnetic heads attached diagonally at 180 degrees to a rotating drum are provided, and one of the plurality of sets is provided. The width of the pair of playback heads constituting the set is at least 1.5 times the recording track pitch,
1. A magnetic recording and reproducing apparatus characterized in that during reproduction, tracking is performed by a magnetic head other than the reproducing head, and the reproducing head only reproduces a sub data area and a main data area.