JPH0656642B2 - Rotating head type recording or reproducing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary head type recording apparatus, and particularly to a plurality of juxtaposed areas each extending in the longitudinal direction of a tape-shaped recording medium, by a rotary head for each area. The present invention relates to a device for recording an information signal.

<Description of Prior Art> In recent years, in the field of magnetic recording, high-density recording has been pursued, and even in a video tape recorder (VTR), the tape traveling speed is reduced to perform higher-density magnetic recording. There is. Therefore, if the audio signal is recorded by using a fixed head as in the conventional case, the relative speed cannot be made large and the reproduced sound quality is deteriorated. Therefore, as one solution to this problem, there is a method in which the length of the track formed by the rotary head is made longer than in the conventional case, and the time axis-compressed audio signal is sequentially recorded in the extended portion.

For example, in a rotary 2 head helical scan type VTR, magnetic tape was wound around 180 ° or more on a conventional rotary cylinder, but (180+
A VTR has been devised which records an audio signal compressed by PCM and time-axis-compressed in an extra wound portion of θ) ° or more. FIG. 1 is a diagram showing a tape traveling system of such a VTR, and FIG. 2 is a diagram showing recording tracks on a magnetic tape by the VTR shown in FIG. In the figure, 1 is a magnetic tape, 2 is a rotating cylinder, 3 and 4 are heads mounted on the cylinder 2 with a phase difference of 180 ° and having different azimuth angles, 5 is a video area portion of a track formed on the tape 1, 6 is also an audio area portion.
The video area 5 is a portion where the heads 3 and 4 trace the tape at 180 ° of the rotating cylinder 2, the audio area 6
Is a portion where the heads 3 and 4 trace the tape at the angle of θ ° of the rotary cylinder 2. The second figure _f 1 ~f ₄ indicates the frequency of the tracking pilot signal superimposed on the track in a known 4-frequency system, the relationship between the frequency _{(f 2 ~f 1) = f} 3 -f in _{4 ≒ f H, f 4 -f} 2
≈2f _H. However, f _H indicates the horizontal scanning frequency of the video signal.

In this way, the sound quality when reproducing the audio signal compressed into the PCM in the audio area and compressed on the time axis is considerably high, and is as good as the sound quality of the audio dedicated device for recording and reproducing the analog signal.

On the other hand, it has been proposed to record another audio signal in the video area 5 in the VTR as described above. That is, for example, when θ = 36, if the rotary head rotates by 180 °, there will be 5 other audio regions such as 6.
One is provided. By recording the time-axis compressed audio signal in each area independently, an audio-only tape recorder capable of recording a total of 6 channels of audio signals can be obtained.

The tape recorder will be briefly described below. FIG. 3 is a diagram showing a tape running system of the above-mentioned tape recorder, and FIG. 4 is a diagram showing recording loci on the tape by this tape recorder. Incidentally, the numbering is shared with FIG. 1 and FIG.

In FIG. 4, CH1 to CH6 respectively trace head 3 or head 4 from A to B, B to C, C to D, D to E, E to F, and F to G in FIG. This is an area in which the audio signal is recorded during a certain period. It is possible to separately record audio signals in each area, and so-called azimuth overwriting is performed in each area, but the tracks in each area CH1 to CH6 do not have to be directly on the same track. The pilot signal for tracking control is recorded in each area. It is assumed that each area is recorded with a predetermined rotation (f ₁ → f ₂ → f ₃ → f ₄ ). There is no correlation between them.

Areas indicated by CH1 to CH3 are tape 1 in FIG.
Is recorded and reproduced when traveling in the direction shown by arrow 7 at a predetermined speed, and the area shown by CH4 to CH6 is recorded and reproduced when traveling in the direction also shown by arrow 9. Therefore, the fourth
As shown in the figure, the slopes of the tracks in the regions CH1 to CH3 are slightly different from the slopes of the tracks in the regions CH4 to CH6. However, the difference in relative speed at this time is not a problem because the difference due to the running of the tape 1 is extremely smaller than that due to the rotation of the heads 3 and 4.

FIG. 5 is a time chart of recording / reproduction of the tape recorder as described above. In the figure, (a) is a phase detection pulse (PG) generated in synchronism with the rotation of the cylinder 2, and repeats "high level (H)" and "low level (L)" in 1/60 seconds.
It is a square wave of Hz. Further, (b) is P having the opposite polarity to PG (a).
G. Here, it is assumed that PG (a) is H while the head 3 rotates from B to G in FIG. 3, and PG (b) is H while the head 4 also rotates from B to G.

FIG. 5 (c) is a pulse for reading data obtained from PG (a), in order to sample the audio signal every other field for the period corresponding to one field (1/60 seconds) of the video signal. belongs to. Fig. 5 (d)
Indicates a signal processing period H for adding error correction redundancy code or the like to the sampled audio data for one field by using a RAM or the like. FIG. 5 (e) shows the period of data recording by H, and shows the timing of recording the recording data obtained by the above-mentioned signal processing on the tape 1.

For example, when the signal flow is temporally traced using FIG. 5, t
Data sampled during the period of 1 to t3 (head 3 is moving from B to G) is t3 to t5 (head 3 is from G to A).
Signal processing is performed at t5 to t6 (Head 3 is A to B)
Will be recorded during the period. That is, by head 3, C in FIG.
It is recorded in the area of H1. On the other hand, the data sampled during the period when PG (b) is H is subjected to signal processing at the same timing and is recorded in the CH1 area by the head 4.

FIG. 5 (f) shows a PG in which PG (a) is phase-shifted by a predetermined phase (here, 36 ° for one area).

Hereinafter, a case where an audio signal is recorded by PG (f) and G (not shown) having an inverse characteristic will be described. The data sampled at t2 to t4 in FIG. 5 are t4 to t6.
During this period, signal processing is performed according to the signal shown in FIG.
The period from t7 to t7 is recorded according to the signal shown in FIG. That is, the head 3 records in the area indicated by CH2 in FIG. 4 while the head 3 traces B to C. Similarly, the data sampled during the period from t4 to t7 is recorded by the head 4 in the area indicated by CH2.

Next, the operation of reproducing the signal recorded in the area indicated by CH2 will be described.

The data read from the tape 1 by the head 3 is shown in FIG.
According to the signal shown in (h), t6 to t7 (same for t1 to t2)
At time t7 to t8 (t
2 to t3), signal processing opposite to that at the time of recording is performed. That is, error correction or the like is performed during this period, and the reproduction audio signal is output at t8 to t9 (t3 to t6) according to the signal shown in FIG. 5 (j). Of course, the reproducing operation by the head 4 is performed with a phase difference of 180 ° with respect to the above-mentioned operation, so that a continuous reproducing audio signal can be obtained.

Also for other regions CH3 to CH6, PG (a) is set to n.
It goes without saying that it is sufficient to shift the phase by × 36 ° and perform the above-mentioned recording / reproducing operation based on this, and this does not depend on the running direction of the tape.

In this way, a VTR as an audio-only machine with multiple channels
Can be used. The problem with such an audio-only machine with multiple channels is that it can be divided into multiple channels.
It is difficult to understand the usage status of each channel.

<Object of the Invention> In view of the background as described above, an object of the present invention is to provide a rotary head type recording apparatus in which the recording condition of each area can be easily grasped and which is extremely easy to use.

<Explanation by Examples> Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 6 is a diagram showing a schematic configuration of a tape recorder as one embodiment of the present invention. In FIG. 6, the same components as those shown in FIGS. 1 to 4 are designated by the same reference numerals.

PG obtained from the rotation detector 11 of the rotating cylinder 2 is supplied to the motor control circuit 15 to rotate the cylinder 2 at a predetermined rotation speed and a predetermined rotation phase. A rotation detector of the flywheel 14 of the 12-capstan 13 is supplied to the output motor control circuit 15 of the rotation detector 12, and controls the rotation of the capstan 13 at a predetermined speed during recording.

On the other hand, the above-mentioned PG is supplied to the window pulse generating circuit 16 and the gate pulse generating circuit 17. FIG. 7 is a timing chart for explaining the phase relationship between the window pulse and the gate pulse with respect to PG.

FIG. 7 (a) is a PG, and the head 3 is B in FIG.
It becomes high level while moving from point G to point G. Fig. 7 (b) ~
(g) is a window pulse indicating the recording / reproducing timing of each of the areas CH1 to CH6. In FIG. 7, the solid line is for the head 3 and the dotted line is for the head 4.

By operating the operation unit 18 manually, an operation mode such as recording and reproduction and an area to be recorded and reproduced are designated. Based on this data, the area designating circuit 19 supplies the area designating data to the gate pulse generating circuit 17 to obtain a desired gate pulse.

The control gate pulse of the gate circuit 20 is selectively supplied to each of the head 3 and the head 4 based on the area designation data, though the window pulse (shown in FIGS. 7B to 7G) is selected. If the area shown in CH2 in FIG. 4 is designated, the gate circuit 20 is controlled by the window pulse shown in FIG. 7 (c).

At the time of recording, the analog audio signal input from the terminal 21 is sampled at the above-mentioned timing relating to the window pulse (c), converted into digital data, and then subjected to the above-mentioned signal processing. The recording audio data thus obtained is the tracking pilot signal generated by the rotation of f ₁ → f ₂ → f ₃ → f ₄ from the pilot signal generating circuit 23 for each field and the pilot signal having a predetermined frequency _5. The mixed signal with (generated by the oscillator 60) is added by the adder 24. It is appropriately gated by the output gate circuit 20 of the adder 24 as described above, and is written in the region CH2 by the heads 3 and 4. Therefore, for all tracks other than the tracking pilot signal,
A pilot signal with a frequency of ₅ will be recorded with the PCM audio signal. By the way, the frequency of ₅ needs to be not affected by the azimuth angle and lower than the exclusive band of the PCM audio signal.

During reproduction, the reproduction signals of the heads 3 and 4 are supplied to the low pass filter (LPF) 35 and the PCM audio circuit 22 via the gate circuit 20 by the same window pulse (c). Contrary to recording, the PCM audio circuit 22 performs signal processing such as error correction, time axis expansion, digital-analog conversion, etc., and outputs a reproduced analog audio signal from the terminal 21a.

The LPF 25 separates the above tracking pilot signal and supplies it to the ATF circuit 26. The ATF circuit 26 is a circuit for obtaining a tracking error signal according to a well-known four-frequency system. It is well known to use. The tracking error signal thus obtained is supplied to the motor control circuit 15 to control the scanning of the tape 1 during reproduction through the capstan 13,
Performs tracking control.

On the other hand, the gate circuit 27 is controlled by the gate pulse shown in FIGS. 7 (h) and 7 (i) output from the gate pulse generating circuit 17. That is, the reproduction signal from the area other than the reproduction area is supplied to the area discrimination circuit 28.

The operation of the area discrimination circuit 28 will be described below. 8th
FIG. 9 is a diagram showing a specific example of the area discriminating circuit 28, and FIG. 9 is a timing chart for explaining the operation timing of each part in FIG.

In FIG. 8, reference numerals 30 and 33 denote terminals to which reproduction signals of the heads 3 and 4 via the gate circuit 27 are supplied, and 31, 34.
Are terminals to which the above-mentioned gate pulse (FIGS. 7 (h) and (i)) are respectively supplied, and 32 is a terminal to which PG is supplied.

As is apparent from the figure, the circuit configuration is composed of a discrimination circuit 37 for the A head 3, a discrimination circuit 38 for the B head 4, and a decoder 47 for serial-parallel converting the outputs of these and outputting it as 6-bit data. Since the determination circuits 37 and 38 have the same configuration, the internal details of the circuit 38 are omitted.

The operation of the area discriminating circuit 28 will be described below. Here, for the sake of explanation, the area CH2 is the reproduction area, the area CH1,
It is assumed that CH4 and CH6 are recorded areas and areas CH3 and CH5 are unrecorded areas.

The respective time constants of the monomulti group 42 triggered by the rising edge of PG (shown in FIG. 9 (a)) are shown in FIG. 9 (e).
~ (I) is specified. That is, Δt is a minute time Then, it corresponds to the Nth channel counting from CH1, and the time constant is expressed by the formula, when N = 1, Δt (sec), and when N is 2 or more. Becomes

Next, the mono-multi group 43, which is triggered by the trailing edge of the output group of the mono-multi group 42, produces 6 types of pulses having a constant width. The time constant of each of these mono-multi groups 43 is about The degree. With this pulse (shown in FIGS. 9 (j) to 9 (q)), detection can be performed at the center position of each region. All the outputs of the mono-multi group 43 are supplied to an OR gate 44, which are supplied to the ungate 45 as sampling pulses and also used as a clock for serial-parallel conversion of the decoder 47.

The AND gate 45 takes the logical product of the output of the OR gate 44 and the gate pulse (shown in FIG. 9 (c)),
The recording status is determined only in the area other than the reproduction area.

On the other hand, the reproduction signal is supplied to the BPF 39 and the pyro signal having the frequency of ₅ is separated. BPF39
The output (shown in FIG. 9 (q)) is detected by the detection circuit 40 and then compared with the reference voltage by the comparison circuit 41, and the output of the comparison circuit 41 is sampled by the AND gate 46. This output, that is, the signal indicating the recording status of each area is shown in FIG. 9 (t). This signal is output from the terminals 48 to 53 as parallel data corresponding to each area by passing through the decoder 47.

That is, if each area CH1 to CH6 has been recorded, the terminal 48
The output signals of ~ 53 are H, and L when they are not recorded. These parallel data are supplied to the display device 29 composed of an LED or the like to let the user recognize the recording status of each area.

According to the tape recorder of the above-described embodiment, it is possible to simultaneously discriminate the recording status of each area having multiple channels.

In the above-described embodiment, the recording status of each area is determined at the time of reproduction, but the recording status of each area can be similarly determined at the time of recording or high-speed tape feeding. Needless to say. If the magnetic tape 1 can be traced by the rotating heads 3 and 4, the recording status can be immediately discriminated.

<Explanation of Effects> As described above, according to the present invention, it is possible to instantly grasp the recording status of the entire area by using only the output of the rotary head, and to obtain the rotary head type recording or reproducing apparatus which is extremely convenient for the user. It is a thing.

[Brief description of drawings]

FIG. 1 is a diagram showing a tape traveling system of a conventional VTR, FIG. 2 is a diagram showing a recording track on a magnetic tape by the VTR shown in FIG. 1, and FIG. 3 is a tape traveling system of a multi-channel tape recorder. FIG. 4, FIG. 4 is a diagram showing a recording track on a magnetic tape by the tape recorder shown in FIG. 3, FIG. 5 is a time chart of recording / reproducing of the tape recorder shown in FIG. 3, and FIG. FIG. 7 is a diagram showing a schematic configuration of a tape recorder as one embodiment, FIG. 7 is a timing chart for explaining a phase relationship between a window pulse and a gate pulse with respect to PG, and FIG. 8 is a region discrimination circuit in FIG. FIG. 9 shows a specific example, and FIG. 9 is a timing chart for explaining the operation timing of each part in FIG. 1 is a magnetic tape as a recording medium, 3 and 4 are rotating heads, 16 is a window pulse generating circuit, 17 is a gate pulse generating circuit, 28 is a region discriminating circuit, 29 is an indicator, 39
Is a BPF for separating a pilot signal of a specific frequency, 40
Is a detection circuit, and 47 is a decoder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirohisa Takahashi 770 Shimonoge, Takatsu-ku, Kawasaki City, Kanagawa Prefecture, Tamagawa Plant, Canon Inc. (72) Kenichi Nagasawa 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc. Company Tamagawa Office

Claims (1)

[Claims] 1. A head for recording / reproducing an information signal and a pilot signal while tracing in an oblique direction with respect to a longitudinal direction of a tape-shaped recording medium, wherein any one of a plurality of areas of the head in different tracing directions is provided. A rotary head type recording or reproducing apparatus for selectively recording and reproducing the information signal and the pilot signal, wherein the detecting means detects the presence or absence of the pilot signal in the output signal of the rotary head, and the plurality of areas. And a discriminating means for discriminating the recording state of each area by detecting the presence / absence of the detection output of the detecting means at a timing corresponding to the above.