JPH0341655A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To accurately reproduce a data by providing a speed control means for shifting the position of a recording track by a portion corresponding to an amt. of protruding a head to one side of the recording track at the time of reproducing by accelerating a traveling speed at the time of changing a reproducing operation in the midst of this mode over to a recording operation. CONSTITUTION:When the reproducing operation is changed in the midst of this mode over to the recording operation, a changeover signal (n) to be outputted from a control circuit 25 is changed from its L level to H level, and a changeover contact 23a of a changeover switch 23 is changed into the state of connecting to the side of an input terminal B. Then, the traveling speed of a magnetic tape is accelerated for a fixed time, and as a result, a first recording track to be newly written on the magnetic tape immediately after the changeover is shifted into a position not to be overlapped with a last recording track to be scanned immediately before the changeover. By this method, the recording track is never overlapped with a part of the last recording track to be scanned immediately before the changeover, and a smooth consecutive recording can be carried out, and then a correct data can be reproduced when this magnetic tape is reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention records data on a magnetic tape by scanning the magnetic tape in a direction crossing the running direction of the magnetic tape with a head disposed on a rotating drum. Alternatively, the present invention relates to a recording and reproducing apparatus that reproduces data from a magnetic tape.

Conventional technology PCM (Pulse Code M
DAT that records signals with high density
(1 g 1 tal^Idi.

In a rotating head type magnetic recording/reproducing device such as a tape recorder, two heads 2a and 2b, which are used for both recording and reproduction, are separated from each other on the circumference of a rotating drum 1, as shown in FIG. What is provided is used,
Data is recorded on the magnetic tape using two heads 2a,
2b, the magnetic tape is alternately scanned in a direction intersecting the running direction of the magnetic tape.

FIG. 5 is a plan view schematically showing a magnetic tape 4 on which recording tracks 3 have been sequentially written by the above-described recording operation. In the figure, the recording track 3 marked with the symbol A indicates the recording track written by one of the heads 2a, and the recording track 3 with the rf number B by one inch is written by the other head 2L, I. shows the loaded recording trunk.

Further, reproduction of data from the magnetic tape 4 is performed by alternately scanning each recording track 3 on the magnetic tape 4 using the two heads 2a and 2b.

6th (2!) is a plan view schematically showing the positional relationship between the recording track 3 and the heads 2a, 2b during the above-mentioned reproduction operation. In the same figure, the head 2 scanning on the recording track 3
The width dimension Tw of a and 2b is larger than the track pitch Tp (width dimension of the recording track 3). Therefore, during the reproduction operation, the heads 2 EL, 2 are read from both sides of the recording track 3.
A part of b is left protruding.

Problems to be Solved by the Invention However, in the case of the above-mentioned conventional recording and reproducing apparatus, when switching to recording operation in the middle of reproducing operation, the trunk and switch Tp of the recording track 3 immediately before switching is turned upside down. When the magnetic tape is played back next time, the ATF (＾auto Track Findil) is
lg) There was a problem in that the servo was disturbed and accurate data could not be reproduced.

FIG. 7 shows a track pattern of the magnetic tape 4 shown to explain the above-mentioned switching operation.
) shows the track pattern before switching to the recording operation IY, and FIG. 7 (2>) shows the final track pattern after switching to the recording operation.

If the reproducing operation is progressing in the direction shown by the arrow P in FIG. A part of the head 2a that scans will protrude to the side of the recording track 3 that was scanned immediately before switching (the amount of protrusion is (T w - T p )/2
>. As a result, as shown in FIG. 7(2), the width of the recording l/rack 3 (indicated by B) immediately before switching is increased by the first recording track 3 (indicated by symbol A') newly written immediately after switching. is the protrusion Ji (T w
- T P )/2.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a recording and reproducing apparatus that can accurately reproduce data without narrowing the track pitch even when switching to a recording operation midway through a reproducing operation and connecting the data.

Means for Solving the Problems The present invention records data on a magnetic tape by sequentially scanning a magnetic tape in a direction crossing the running direction of the magnetic tape with a head mounted on a rotating drum. In a recording/playback device designed to play back data, when switching from a playback operation to a recording operation, the running speed of the magnetic tape is increased for a certain period of time to determine the position of a new recording track to be written on the magnetic tape. , recording track piece ff of the head during playback! This recording/reproducing apparatus is characterized in that it includes a speed control means for shifting by an amount corresponding to the amount of protrusion of Il\.

Effect According to the present invention, when the recording operation is switched from the middle of the reproduction operation, the running speed of the magnetic tape increases for a certain period of time, and as a result, the first new write on the magnetic tape immediately after the switching is made. The recording track is shifted to a position where it does not overlap with the last recording track scanned immediately before switching. Therefore, the fit &
The track pitch of the recording track is not narrowed, and accurate data will be reproduced the next time.

Embodiment FIG. 1 is a block diagram showing a schematic configuration of a capstan servo am in a rotary head type magnetic recording/reproducing apparatus which is an embodiment of the present invention.

In FIG. 1, a capstan motor 11 is a drive motor for running a magnetic tape, and the pulse signal output from this capstan motor 11 is increased by @812.
The signal is inputted to the speed servo 13 and the phase servo 14 via.

The speed servo 13 includes a speed error detection circuit 15 that detects an error between a predetermined rotational speed of the capstan motor 11 and the current rotational speed based on the output signal of the capstan motor 11, and an output signal of this circuit. 1 out of 2 people
It is composed of an OR gate 16 as an input, and a low-pass filter 17 that receives the output of the OR gate 16 as a CPE (capstan phase error) signal.

The phase servo 14 also includes a frequency dividing circuit 18 that frequency divides the output signal of the capstan motor 11, and compares the frequency divided signal obtained by this circuit with another reference signal to determine the phase of the frequency divided signal with respect to the reference signal. It consists of a phase error detection circuit 19 that detects errors, and a low pass filter 20 that receives the output of this circuit as a CPE (capstan phase error) signal.

Tracking error detection time i? fi21 is a circuit that detects the displacement of the head from the recording track based on the reproduction signal read from the magnetic tape during reproduction study.

The low-pass filter 17 of the speed servo 13 is connected to the next-stage distributor 22, and the tracking error detection circuit 1
The low-pass filter 20 of the PI 21 and the phase servo 14 is connected to the distribution 2S22 through a changeover switch 23. This distribution device 22 allows the phase servo The control signal 311 output from the tracking error detection circuit 21 or the control signal 13 output from the tracking error detection circuit 21 is superimposed at a fixed distribution, and the superimposed control signal is amplified by the control amplifier 24 to control the rotational speed of the capstan motor 11. It is given as a control signal.

The control circuit 25 is constituted by a microcomputer and sends a switching signal n for switching and controlling the changeover switch 23 and a reset signal Q to be applied to the latch circuit 26.
It also has the function to output .

The latch circuit 26 receives the switching signal n outputted from the control circuit 25 at its clock input terminal ck, and receives the reset signal Q outputted from the same control circuit 25 at its reset input terminal R. Further, the output signal p taken out from the output terminal Q of the latch circuit 26 is transmitted to the speed servo 13.
is given as the other one person's power of the OR gate 16. Note that in this rotary head type magnetic recording/reproducing device, there are also two
A rotating head mechanism with two heads is used.

FIG. 2 is a timing chart showing the operation of the capstan servo mechanism. The operation of the capstan servo mechanism will be described below with reference to FIG.

When the reproducing operation is being performed, the switching signal n output from the control circuit 25 is set to a low level (hereinafter abbreviated as L level) as shown in FIG. 2 (1).
As a result, the changeover contact 23 a of the changeover switch 23
is connected to the input terminal A side. therefore,
A control signal output from the speed servo 13 and a control signal output from the tracking error detection circuit 21 are sent to the distributor 22 . During this time, the reset signal Q given from the gtn circuit 25 to the latch circuit 26 is
) is maintained at a high level (hereinafter abbreviated as 4 level), and the output signal p of the latch circuit 26 is also maintained at an L level as shown in FIG. 2(3). That is, the CSE signal which is the output of the ()R gate 16 of the speed servo 13 corresponds to the output of the speed error detection circuit 15, and the capstan motor 11 is controlled based on the control signal sent to the distributor 22. The rotation speed is controlled to be constant, and the magnetic tape runs at a constant speed accordingly.

When the recording operation is switched in the middle of the above-mentioned reproducing operation, the switching signal n output from the control circuit 25 is as shown in FIG.
), the L level switches to level 1 (level 1),
As a result, the changeover contact 23a of the changeover switch 23 is switched to the state connected to the input terminal B side. Therefore, the distributor 22 receives the control signal rnf3 output from the speed servo 13 and the control signal rnf3 output from the phase servo 14.
I can send it to you. At this time, as the switching signal r1 switches from L level to H level, this switching signal n
Since the receiving latch circuit 26 holds this, the output signal p of the latch circuit 26 switches from the L level to the H level, as shown in FIG. 2(3). As a result, the speed servo 13. C8E which is the output of R gate 16
The signal becomes the I level in response to the output signal p from the latch circuit 26. This condition is caused by the control circuit 25 or the parachute rotation
326 is switched to the L level as shown in FIG. 2 (2), and the latching time F! ? r2
The output signal p of No. 6 returns to the L level again as shown in the second [J(3). is maintained until the time gorge. Therefore, the C S E signal obtained for the speed servo 13 is forcibly maintained at level 11 for the above-mentioned time, and the rotation speed is controlled based on the control signal sent to the distributor 22. During this period, the capstan motor 11 receives the FW! at a higher speed than the constant speed during playback! The magnetic tag #J travels at high speed accordingly. After the above-mentioned time t has elapsed, the CSE signal 5 of the speed servo 13 returns to the value corresponding to the output of the speed error detection circuit 15, so the rotational speed of the capstan motor 11 returns to the original speed, and the magnetic data changes accordingly. 1 also returns to its original running speed.

Figure 3 shows the trunk pattern of the magnetic tape 4 during the above switching operation, of which Figure 3 (1) shows the track pattern before switching to the recording operation (in the case of Figure 7 (1)). Figure 3 (2) shows the recorded motion "
The track pattern after being switched to P is shown.

Assuming that the above-mentioned switching operation is performed from the position indicated by the symbol m in the same figure while the regeneration operation is progressing in the direction indicated by the arrow P in Fig. 3 (1), it is assumed that the above switching operation is performed from the position indicated by the symbol m in the figure. During this period, the running speed of the magnetic tape 4 is switched from the steady speed up to that point to a predetermined high speed, so that the recording track 3 that was being scanned immediately before the switching, as shown in No. 312I(2),
(Denoted by code B) is the first magnetic tape-1 immediately after switching.
(The recording track 3 recorded by the head is indicated by reference numeral A') and advances to a position where no sweat occurs. Therefore, the track pitch 4 of the recording track 3 immediately before the refresh is not narrowed by the newly written recording track 3, and even when this magnetic tape 1 is played back next time, the above-mentioned splicing point will not be narrowed due to the newly written recording track 3. A
The TF servo will not be disturbed and accurate data can be reproduced.

Effects of the Invention As described above, according to the recording and reproducing apparatus of the present invention, the running speed of the magnetic tape is switched to high speed for a certain period of time immediately after the reproduction operation is switched from t to recording operation. So the first recording trunk is written newly onto the magnetic tape immediately after switching.

There is no overlap with a part of the last recording track scanned immediately before switching, so smooth succession can be performed, and even when the magnetic data 1 is reproduced, accurate data can be reproduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a capstan servo mechanism in a rotary head type magnetic recording/reproducing device which is an embodiment of the present invention, FIG. 2 is a timing chart showing its operation, and FIG. Fig. 4 is a plan view showing the schematic structure of a rotating drum in a rotating head type magnetic recording/reproducing device; FIG. 6 is a plan view showing a magnetic tape on which a recording trunk has been written by a type magnetic recording/reproducing device;
FIG. 7 is an explanatory diagram showing changes in the track pattern on a magnetic tape when splicing is performed using a conventional rotary head type magnetic recording/reproducing apparatus.

Claims (1)

[Claims] Recording in which a head attached to a rotating drum sequentially scans a magnetic tape in a direction crossing the running direction of the tape to record data on the magnetic tape or to reproduce data from the magnetic tape. In a playback device, when the playback operation is switched to the recording operation, the running speed of the magnetic tape is increased for a certain period of time, and the position of the new recording track written on the magnetic tape is adjusted to the recording track of the head during playback. A recording/reproducing device characterized by comprising a speed control means for shifting by an amount corresponding to an amount of protrusion to one side.