JPS60143480A - Magnetic recording regenerator - Google Patents

Abstract

PURPOSE:To record with satisfactory interchangeability by making an automatic tracking circuit as a just track while a standard tape is reproduced adjusting the delay amount of a variable delay circuit, and obtaining the recording with the same recording pattern as that of the standard tape. CONSTITUTION:A standard tape 31 records block synchronizing signals B1 and B2 by magnetic heads H1 and H2 which are installed normally, and it records the standard magnetic pattern. Therefore, the signals B1 and B2 reproduced by the heads H1 and H2 are shown by A and B, and a delayed block synchronizing signal B0 which is obtained at the output side of a delay circuit 13 is shown by C. Since the output signal of a counter 12 which is latched by a latch circuit 14 is Dfs when reproduction is executed by the heads H1 and H2, the just track is obtained when an oscillation frequency Rf of a variable frequency oscillation circuit 17 is ussumed as Dfs. The oscillation frequency of the circuit 17 is set as Dfs of the reference value beforehand. Then, the oscillation frequency Rf of the circuit 17 is adjusted while the standard tape 31 is reproduced so that the just track will be obtained. Then, the delay time of a variable delay circuit 26 of the recording system is set as the value which is equivalent to DELTARf.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus suitable for application to digital VTRs and the like.

Background Art and Problems There has been proposed a digital VTR that converts video signals into digital signals for recording and reproduction.

In general, digital VTRs have a wide signal band, so for example, one field of digital video signal is divided into 5 parts in the NTSC system, and 6 parts in the PAL or SECAM system. 6. A channel encoding circuit is used to distribute the field signal into two channels, which are recorded on a magnetic tape using magnetic heads having magnetic gaps with different azimuths to form adjacent magnetic tracks, and then reproduced. I was trying to do that. Therefore, in such a digital VTR, 180'
There are two sets of rotating magnetic heads arranged at an angular division of , and each set consists of two rotating magnetic heads disposed close to each other having magnetic gaps having different azimuths as described above. Then, each set of rotating magnetic heads records the chef yields on the magnetic tape so as to alternately form inclined magnetic tracks using two sets of rotating magnetic heads, and the recorded tracks are reproduced.

FIG. 1 shows inclined magnetic tracks T, which are arranged close together.

T2 and a rotating magnetic head H1 for recording and reproducing the same.
I(2 is shown.gl#g2 is the rotating magnetic head H,
, B2 have different azimuths. The digital video signals recorded on these inclined magnetic tracks 'r and t'r2 are divided into blocks, and an encoding circuit and a channel encoding circuit are used for error correction and correction in units of one block or several blocks. After being encoded through
The magnetic tracks T, , T2 are reproduced by the rotary magnetic heads H, , B2, and the reproduced signals are sent to the channel decoding circuit and error correction circuit. BL is supplied to a decoding circuit and decoded to obtain the original digital video signal.
B1.2 shows the 1f lock of the digital video signal recorded in B1.2. B2c magnetic track T1. The block synchronization signal of each block of T2 is shown. In the example of FIG. 1, the adjacent magnetic tracks 'r1. 'r2 block synchronization signal B
, , B2 are recorded with a predetermined phase in a steady state.

In the inclined magnetic tracks T, , T2 in FIG. 1, only digital video signals were recorded, but as shown in FIG. This is a case where a digital audio signal A is supplied to the terminal. In this case, the block synchronization signal B is also applied to the digital audio signal part.
, , B2 are arranged in the same way as a digital video signal.

The width of such inclined magnetic tracks T, , 'r2 is narrowed for high-density recording. Therefore, mistracking is relatively likely to occur during playback.

Therefore, as shown in Japanese Patent Application Laid-Open No. 57-198566, auto-tracking is performed using the phases of synchronization signals B1 and B2 having the same period, such as block synchronization signals recorded on inclined magnetic tracks close to each other. is proposed.

Below, with reference to FIGS. 3 and 4, an example of this auto-tracking will be described in detail.
, B2 are rotary heads having magnetic gaps glpg2 with different azimuths, and may be used only for reproduction or for both recording and reproduction. The reproduction signal from the rotating magnetic head ■1 r B2 is sent to the reproduction amplifier (11) and (12).

supplied respectively. The reproduced signal from the reproducer 77'' (11)-(12) is transmitted to the bit synchronization circuit (21) and PLL (3,
). The clock signal (for example, 100MHz) obtained from the PLL (31) is sent to the bit synchronization circuit (2).
1), a synchronized digital video signal is obtained at its output. Also, playback amplifier (
12) The output of Yoshi is similarly supplied to the bit synchronization circuit (22) and PLL (32). The clock signal (for example 100 MHz) obtained by the PLL (32) is supplied to the bit synchronization circuit (22). A synchronized digital video signal is then obtained at the output side of the bit synchronization circuit (22).

Then, the block synchronization signal B1. as shown in FIG. 1 or FIG. 2 described above. Since this is a case where B2 has a predetermined phase difference in a steady state, a common block synchronization signal extraction circuit (7) is provided, and bit synchronization circuits (21)-(22)
, PLL (31), and (32), the synchronized digital video signals and clock signals are switched and supplied to the block synchronization signal extraction circuit (7).

Changeover switch (4) switches (5) and (6) to the right
-, the switch (5) switches the output of the bit synchronization circuit (2,), (two) and supplies it to the extraction circuit (7), and the switch (6) switches the output of the bit synchronization circuit (2,), (2,) and supplies it to the extraction circuit (7). The clock signal is switched and supplied to the extraction circuit (7). and,
The block synchronization signals B, , B2 from the extraction circuit (7) are supplied to a detection circuit (8) that detects the phase difference of the synchronization signals. A clock signal from the switch (6) is supplied to this detection circuit (8). The output of the extraction circuit (7) is supplied to the changeover switch (4) as a changeover control signal, and the switches (5) and (6) are switched in conjunction. The output of the detection circuit (8) is connected to the phase sensor circuit (9).
), and another control signal is supplied to the cabzukun motor α1 to control its rotation, and during playback, the rotary magnetic head Ml #H2 moves along the inclined magnetic tracks T, , T.
It is controlled to accurately track 2.

Next, the operation of the circuit shown in FIG. 3 will be explained with reference to FIG. 4A and 4B show block synchronization signals B, . . . B2 extracted from the reproduced signals of the rotating magnetic head) I, . . . B2 obtained by the block synchronous signal extraction circuit (7). Then, the block synchronization signal B11B2 is supplied to the detection circuit (8), so that its phase difference becomes a rectangular wave iJ? as shown in FIG. 4C. This rectangular wave pulse detected as a pulse and the clock signal of the changeover switch (6) are supplied to the AND/DART and block synchronization signal B1. A according to the phase difference of B2? Intermittent pulses as shown in the fourth diagram of the Luss number are obtained. This intermittent noculus is the circuit (9
), the capstan motor α1 is digitally controlled.

When reproducing a plurality of inclined magnetic tracks of a magnetic tape in which information signals including the above-mentioned synchronization signal of the same period form a plurality of closely spaced inclined magnetic tracks having different recording azimuths, using a plurality of magnetic heads, Tracking errors can be easily detected using synchronization signals recorded on each magnetic track.

Therefore, auto-tracking becomes possible by supplying this tracking error to the circuit from the capstan motor sensor. 'Also, in some cases, a rotating magnetic head is attached to a rotating disk via an electro-mechanical converter such as a bimorph, and auto-tracking is performed by controlling the electro-mechanical converter using a tracking error signal. You can also do that.

By the way, generally speaking, the rotating magnetic head H1 of a magnetic recording/reproducing device
, H2, the spacing between the magnetic gaps g11g2 is not necessarily constant, but has an error of about 50 μm, for example, due to mounting errors. If the spacing of such magnetic air gaps ¥15g2 is larger or smaller than the standard value, the spacing on the magnetic tape of block synchronization signals B, B2 recorded by such rotating magnetic heads H1yH2 is the standard value. This recording magnetic tape is placed in another magnetic gap of 1N+g.
When data is reproduced using a magnetic recording/reproducing apparatus having a configuration shown in FIG. 3, for example, where the distance between two discs is different, there is an inconvenience that the tracking error f cannot be obtained.

OBJECTS OF THE INVENTION In view of the above, the present invention provides a rotating magnetic head)11. Even if there is an installation error in the magnetic gap g1#g20 interval of B2, the interval of block synchronization signals B, , B2 on the recorded magnetic tape will be the same as the interval of block synchronization signals B, , B2 on the standard tape. The purpose is to make it possible to record with good compatibility.

Summary of the Invention The present invention provides a magnetic recording and reproducing device having a plurality of magnetic heads with different azimuths. First, while playing back a standard tape, an auto-tracking circuit is adjusted to make the track just right, and then the standard tape is used to determine a track. The delay amount of the variable delay circuit provided in the recording system is adjusted according to the difference between the standard value to be determined and the value obtained in connection with this adjustment, and the recording time is adjusted in accordance with the difference between the reference value and the value obtained in connection with this adjustment. ? According to the present invention, even if there is an installation error in the spacing between the magnetic gaps of a plurality of magnetic heads, the block synchronization signal B1. If the interval of B2 is the same as the interval of block synchronization signals B, , B2 on the standard tape, recording with good compatibility can be performed.

Embodiment Hereinafter, one embodiment of the magnetic recording/reproducing apparatus of the present invention will be described with reference to FIGS. 5 to 8. In FIGS. 5 to 8, parts corresponding to those in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed explanation thereof will be omitted. ' In this example, the auto-tracking circuit of the magnetic recording/reproducing apparatus is constructed as shown in FIG. That is, in FIG. 5, (11B1) indicates the first block synchronization signal input terminal to which the block synchronization signal B1 is supplied, and the block synchronization signal input terminal (IIB, ) supplied to this first block synchronization signal input terminal The signal B1 is supplied to the reset terminal of the counter (b). Further, (11B2) indicates a second block synchronization signal input terminal to which the block synchronization signal B2 is supplied;
The block synchronization signal B2 supplied to the block synchronization signal input terminal (11B2) of the latch circuit α is supplied to the latch timing determination signal input terminal of the latch circuit α via a delay circuit whose delay time is a predetermined time. Further, αO indicates a clock signal input terminal to which a clock signal of frequency f8 is supplied, and the clock signal supplied to this clock signal input terminal (c) is supplied to the clock signal input terminal of the counter. The output signal of this counter (6) is supplied to the input side of the latch circuit α◆, and the output signal of this latch circuit α◆ is supplied to the input side of the latch circuit α◆.
Supplied to one input terminal of Q. Further, α power indicates a variable frequency oscillation circuit, and the output signal of the variable frequency oscillation circuit α power at an oscillation frequency Rf is supplied to the other input terminal of the comparison circuit α→. In this comparison circuit OQ, the frequency signal supplied to one input terminal is supplied to the other input terminal, and an error signal obtained by subtracting the oscillation signals R and f is passed through an integrator α barrel to a digital-to-analog conversion circuit. The analog error signal obtained at the output side of this digital-to-analog conversion circuit a is supplied to the capstan motor c21) via the buffer an f (a), and this capstan motor (2I) Control the tracking by controlling the rotation of the

In this example, the recording system of the magnetic recording/reproducing apparatus is constructed as shown in FIG. That is, in Fig. 6, 2 indicates a video signal input terminal, and the video signal supplied to this video signal input terminal
C), and the digital signal obtained at the output side of this analog-to-digital conversion circuit (2) is supplied to the digital signal processing circuit (2 stations and (C), respectively.The output of this digital signal processing circuit c!4 The signal is supplied to the parallel-to-serial converter circuit (5) via the digital variable delay circuit (c), and the serial digital signal output from this parallel-to-serial converter circuit is recorded and sent to the amplifier circuit (b). It is supplied to the magnetic head H1 through the magnetic head H1.

In addition, the output signal of the digital signal processing circuit (c) is parallel-
The serial digital signal output from the 74 parallel serial converter circuit is supplied to the magnetic head H2 via the recording amplifier circuit. In this example, the configuration is otherwise similar to that of a well-known digital VTR.

In this example, first, let's use the standard chain y'H as shown in the seventh diagram.
Prepare. This standard tape θ force is assumed to be one in which block synchronization signals B and B2 are recorded using standardly attached magnetic heads H1 and H2, and a standard magnetic pattern is recorded. Therefore, when this standard chip 0 is reproduced by the magnetic heads H1 and H2 installed as standard, the block synchronization signals B and B2 are as shown in FIG. 7A and B, and the delay circuit in FIG. (The delayed fT2 clock synchronization signal B0 obtained at the output side of The output signal of counter α latched by circuit a4 is Df8
Therefore, the oscillation frequency R of the variable frequency oscillation circuit a'/)
If f is Df, just track is achieved.

Next, to explain the magnetic recording and reproducing apparatus of this example, when using this standard tape (3 tapes), the variable frequency oscillation circuit shown in FIG. Next, while reproducing this standard Q7''01), adjust the oscillation frequency Rf of the variable frequency oscillation circuit a so that it is just on track.

For example, as shown in Figure 8, when the distance between the magnetic gaps g1 and g2 of the magnetic heads H1 and H2 is shorter than the distance between the magnetic gaps of the standard magnetic head that recorded the 0th standard tape by 1, the reproduced block synchronization The phase of the signal B2 is earlier than that of the signal B1 by a time corresponding to this interval, as shown in FIGS. 8B and A, and the number of output signals of the counter (6) latched by the latch circuit α→ is also reduced. Take the oscillation frequency Rf of the output signal of the variable frequency oscillation circuit a'I) at the time of just tracking, and let the difference between f (nfs-R) be ΔRf. In this eighth diagram, ΔRf>O.

Next, the delay time of the variable delay circuit (2)0 of the recording system shown in FIG. 6 is set to a value corresponding to this ΔRf. In this case, if the distance between the magnetic gaps g1 and g2 is longer than the standard one, ΔRf<O, so a variable delay circuit may be provided on the magnetic head H2 side in FIG. A so-called getter is applied to the delay amount of the variable delay circuit (c), and when ΔRf>O, lRf is further applied H so that ΔRf<O
In this case, it is possible to subtract ΔR1.

When configured as described above, when recording with this magnetic recording/reproducing apparatus, for example, the magnetic heads H1 and H shown in Figure 8 are used.
In the case of relationship 2, the signal recorded on the magnetic head H1 will be recorded with a delay corresponding to the interval.
Block synchronization signals B1 and B2 can be recorded in the same recording number and turn as the standard tape 0th recording turn.

After that, I confirmed that it was a perfect track based on this personal record.

According to this example, since it is possible to record in the same recording pattern as the standard tape, it is possible to perform good reproduction and compatible recording with other magnetic recording and reproducing apparatuses.

It goes without saying that the recording system variable delay circuit (26) may be inserted after the parallel-to-serial conversion circuit is inserted as shown in FIG. Further, the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations can be made without departing from the gist of the present invention.

Effects of the Invention According to the present invention, even if there is an installation error in the gap between the magnetic spaces of a plurality of magnetic heads having different azimuths, the magnetic pattern of the recorded magnetic chip can be made the same as the magnetic pattern on the standard tape. , there is the benefit of being able to perform compatible recordings.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing the grooves and turns of the magnetic track and the magnetic head of a digital VTR, Figure 3 is a configuration diagram showing an example of an auto-tracking device, and Figure 4 is an explanation of Figure 3. FIGS. 5 and 6 are diagrams showing the main parts of an embodiment of the magnetic recording/reproducing apparatus of the present invention, and FIGS. 7 and 8 are diagrams used to explain the present invention, respectively. FIG. 9 is a block diagram showing another example of the recording system. (IIB, ) and (11B2) are the first and second block synchronization signal input terminals, respectively, (b) is a counter, α power is a latch circuit, α power is a clock signal input terminal, α is a comparison circuit, α power is is a variable frequency oscillation circuit, Qυ is a cazostan motor, ati is a delay circuit, B1 and B2 are block synchronization signals, Hl and H2 are magnetic head percentages, respectively.gj and g2
is the magnetic air gap. ((・1-゛gu I bar Figure 4 Figure 8

Claims (1)

[Claims] In a magnetic recording/reproducing device having a plurality of different magnetic heads, first, while playing a standard tape, the auto-tracking circuit is adjusted to just track, and then the reference value determined by the standard tape is adjusted. The delay amount of the variable delay circuit provided in the recording system is adjusted according to the difference from the value obtained in connection with the above adjustment, so that it is possible to record in the same recording pattern as the recording pattern of the above standard tape during recording. A magnetic recording/reproducing device characterized by: