JP2648338B2 - Magnetic recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic recording device equipped with a monitor head.

[Prior Art] Conventionally, a rotating drum equipped with a monitor head has a
It is configured as shown in the figure. 5 is a rotating drum, 2 is a pair of recording / reproducing heads arranged 180 ° opposite to the rotating drum 5, and 3 is also arranged 180 ° opposite to the rotating drum 5 and is shifted from the head 2 by 90 °. It is a pair of monitor heads provided. FIG. 5 shows a recording track pattern on the magnetic tape 1 obtained by the head having such a configuration. As shown in FIG. 5, the recording track 4a recorded on the tape 1 by the recording / reproducing head 2 at the time of recording is traced by the monitor head 3, and the clogging of the recording / reproducing head 2 is determined by the reproduced output of the monitor head 3 at that time. Then, the same signal is recorded on the tape 1 again by the recording / reproducing head.

[Problems to be Solved by the Invention] However, in the above-described conventional example, clogging of the recording / reproducing head is detected based on the reproduction output of the monitor head, and the same signal is recorded again by the recording / reproducing head. Was.

1) The clogging of the monitor head or the recording / reproducing head cannot be determined.

2) The recording / reproducing head is clogged, and when the same signal is repeatedly recorded, the recording cannot be performed unless the clogging is corrected.

[Means for Solving the Problems] In order to solve such a problem, a magnetic recording apparatus according to the present invention includes a recording head set on a rotating drum, and a recording head mounted on the drum, which is used for recording tracks by the recording head. A recording head for reproducing a recording signal from the recording track during recording of the signal, a detecting unit for detecting an abnormality of the recording head in accordance with a reproduction output of the monitoring head, and a detecting unit for detecting an abnormality of the recording head. When an abnormality is detected,
After the monitor head is shifted in the width direction of the track in a direction opposite to the recording direction, control means for supplying a recording signal to the monitor head is provided.

[Operation] According to the present invention, an abnormality of the recording head is detected by the reproduction output of the monitor head, and when the abnormality is detected, the monitor head is shifted in the width direction of the recording track in a direction opposite to the recording direction. After that, the recording signal is recorded by the monitor head. This enables normal recording even when the recording head is clogged.

EXAMPLES The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a view showing an arrangement of a head according to the present invention, in which 5 is a rotating drum, 2 is a pair of recording / reproducing heads arranged 180 ° opposite to the rotating drum 5,
Reference numeral 3 denotes a pair of monitor heads which are also disposed 180 ° on the rotating drum 5 and shifted by 90 ° from the head 2, and detect clogging of the recording / reproducing head 2. 6
Is a bimorph having a pair of monitor heads 3 attached to both ends inside the rotating drum 5, and moves the monitor head 3 in the width direction of the recording track 4.

At the time of recording / reproduction, a magnetic tape is wound around the rotating drum 5 at a predetermined angle. As shown in FIG. 2, 4a, 4b, 4c, 4d
Indicates a recording track recorded on the magnetic tape 1 by the recording / reproducing head 2. FIG. 2 illustrates the positional relationship between the recording / reproducing head 2 and the monitor head 3 on the recording track 4a. That is, when the recording / reproducing head 2 is at the end of the recording track 4a, the monitor head 3 is at the beginning of the track 4a.

FIG. 3 is a block diagram showing a main part of the magnetic recording / reproducing apparatus according to the present invention. As shown in FIG. 3, at the time of recording, an information signal is digitized by an A / D converter 7, and in a signal processing control 8, addition of redundant bits for error detection and error correction and time axis compression are performed. Then, the data modulation circuit 9 performs 8-10 conversion (8 bits-10 bits). The output signal of the data modulation circuit 9 is amplified by the recording amplifier 10, passes through the switch SW (a), and is recorded on the magnetic tape 1 by the recording / reproducing head 2. Here, the switch SW (a) is controlled by the control circuit 16 and is opened only when the recording / reproducing head 2 is clogged.

Then, the monitor head 3 traces the recording track recorded on the tape by the recording / reproducing head 2 and inputs the reproduced signal to the reproducing amplifier 12 through the switch SW (b). The switch SW (b) is switched and controlled by the control circuit 16 and normally sends a reproduction signal from the monitor head 3 to the reproduction amplifier 12, while, when the recording / reproduction head 2 is clogged, the signal from the recording amplifier 21 is output. The recording signal is passed through the monitor head 3. A recording signal from the data modulation circuit 9 is input to the recording amplifier 21 via three memories 18, 19, and 20 for storing recording signals for three fields.
The reproduction signal from the monitor head 3 input to the reproduction amplifier 12 is amplified, and then the detection circuit 14 detects the presence or absence of an abnormality, and the detection result is input to the control circuit 16.

As shown in FIG. 2, the recording / reproducing head 2 is
When the detection circuit 14 detects the clogging of the recording / reproducing head 2 from the reproduction output when the monitor head 3 reaches the clogging portion of the same track 4a, the control circuit 16 A high-voltage amplifier 17 sends a control signal to move the control signal 3 in the recording track width direction.
The circuit 17 drives the bimorph 6 (the driving mode is shown in FIG. 4), moves the monitor head 3 in the width direction of the recording track, and causes the head 3 to trace the recording track 4d two tracks before. (The locus of the monitor head 3 is indicated by an arrow in FIG. 2). Then, the reproduction output from the recording track 4d of the monitor head 3 is switched by the switch SW.
(B) The signal is input to the detection circuit 14 via the reproduction amplifier 12, and the presence or absence of abnormality in the reproduction output is detected there again. Control circuit 16
Determines the abnormality of the monitor head 3 or the recording / reproducing head 2 based on the detection result from the detection circuit 14. That is, if there is no abnormality in the detection result of the reproduction output of the monitor head 3, it is determined that the recording / reproduction head 2 is clogged. If the recording / reproducing head 2 is clogged, the monitor head 3 traces the recording track 4d and then traces the recording track 4a again by the monitor head 3 after one rotation of the drum. At this time, the switch SW (b) is switched to the recording amplifier 21 side, and the recording signal from the recording amplifier 21 is sent to the monitor head 3. By performing recording with the monitor head 3, normal recording can be performed even when the recording / reproducing head 2 is clogged.

[Effect of the Invention] 1) Abnormality of the recording head can be reliably determined.

2) Normal recording can be performed even if an abnormality such as clogging occurs in the recording head.

[Brief description of the drawings]

FIG. 1 is a diagram showing a head configuration on a drum embodying the present invention, FIG. 2 is a diagram showing a locus of a monitor head embodying the present invention, and FIG. 3 is a diagram showing a main part of a recording / reproducing apparatus according to the present invention. FIG. 4 is a diagram illustrating a bimorph control voltage embodying the present invention, FIG. 5 is a diagram illustrating a locus of a conventional monitor head, and FIG. 6 is a diagram illustrating a conventional head configuration. 1 ... magnetic tape, 2 ... recording / reproducing head, 3 ... monitor head, 4 ... recording track, 5 ... drum, 6 ... bimorph, 7 ... A / D, 8 ... signal processing control, 9 …… Data modulation, 10… Recording amplifier, 11… Switch, 12… Reproduction amplifier, 13… Switch, 14… Detector circuit, 16… Control circuit, 17… High voltage amplifier, 18… Memory 19: Memory, 20: Memory, 21: Recording amplifier.

Claims (1)

(57) [Claims] 1. A recording head set on a rotating drum, and a monitor head installed on the drum and reproducing a recording signal from the recording track while the recording head records a signal on the recording track. Detecting means for detecting an abnormality in the recording head in accordance with the reproduction output of the monitor head; and when the detecting means detects an abnormality in the recording head, the recording direction of the monitor head in the track width direction is detected. And a control unit for supplying a recording signal to the monitor head after shifting in the opposite direction to the above.