JPH0746401B2 - Rotating head type recording or reproducing device - Google Patents

Description

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

<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 rotating 2-head helical scan type VTR, magnetic tape was wound around 180 ° or more on a conventional rotating cylinder, but (180 + θ) ° on the rotating cylinder.
A VTR has been devised which records an audio signal that has been time-compressed and PCM-compressed in the wound and extra wound portions. Fig. 1 is a diagram showing such a VTR tape running system,
FIG. 2 is a diagram showing a recording track on the 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, and 5 is a video area portion of a track formed on the tape 1. Reference numeral 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 rotary cylinder 2, and the audio area 6 is a portion where the heads 3 and 4 trace the tape at θ ° of the rotary cylinder 2. The second
In the figure, f _{1 to} f ₄ indicate the frequencies of the tracking pilot signal superimposed on each track by the well-known four-frequency system, and the frequency relationship is (f ₂ −f ₁ ) = f ₃ −f ₄ ≈ at 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 of the audio signal reproduced into PCM in the audio area and compressed on the time axis is considerably high, and is comparable to the sound quality of the dedicated audio device which records and reproduces 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, when θ = 36, for example, if the rotary head rotates by 180 °, five other audio areas such as 6 are provided. Then, by recording the time-compressed audio signals in each area independently, an audio dedicated 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 represent the period when head 3 or head 4 traces A to B, B to C, C to D, D to E, E to F, F to G, respectively, in FIG. This is the area where the audio signal is recorded. 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 on the same straight line. The pilot signal for tracking control is recorded in each area, but it is assumed that it is recorded in a predetermined rotation (f ₁ → f ₂ → f ₃ → f ₄ ) for each area. There is no correlation between them.

Areas indicated by CH1 to CH3 are recorded and reproduced when the tape 1 is running at a predetermined speed in a direction shown by an arrow 7 in FIG. 3, and areas shown by CH4 to CH6 are also run in a direction shown by an arrow 9. It is recorded and reproduced when Therefore, as shown in FIG. 4, the inclination of each track in the areas CH1 to CH3 and CH4 to C
The slope of each track in the area indicated by H6 is slightly different. However, the difference in relative speed at this time is not a problem because the tape 1 travels much less than the heads 3 and 4 rotate.

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 (hereinafter, PG) generated in synchronization with the rotation of the cylinder 2, which has a frequency of 30 Hz which repeats "high level (H)" and "low level (L)" in 1/60 seconds. It is a square wave. Further, (b) is a PG having a polarity opposite to that of PG (a). Here, in PG (a), the head 3 is B in FIG.
It is assumed that H during rotation from G to G and PG (b) is H during rotation of the head 4 from B to G as well.

FIG. 5 (c) is a pulse for reading data obtained from PG (a), for sampling 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) shows a signal processing period H for adding a redundant code for error correction to the sampled audio data for one field using RAM or changing the arrangement.
Indicate. FIG. 5 (e) shows the period of data recording as H,
The timing of recording the recording data obtained by the above-described signal processing on the tape 1 is shown.

For example, when the signal flow is temporally tracked using FIG. 5, t1
The data sampled during the period from t3 to t3 (while the head 3 is moving from B to G) is subjected to signal processing at t3 to t5 (head 3 is G to A), and t5 to t6 (head 3 is A to B). Will be recorded during the period. That is, it is recorded by the head 3 in the CH1 area in FIG. On the other hand, the data sampled while PG (b) is H is processed at the same timing,
Is recorded in the CH1 area by.

FIG. 5 (f) shows a PG in which the PG (a) is phased by a predetermined phase (here, 36 ° for one area). Hereinafter, a case where an audio signal is recorded by PG (f) and a PG (not shown) having an opposite characteristic will be described. The data sampled from t2 to t4 in FIG. 5 is signal-processed according to the signal shown in FIG. 5 (g) during t4 to t6 and recorded according to the signal shown in FIG. 5 (h) during the period from t6 to t7. . That is, the head 3 records in the area indicated by CH2 in FIG. 4 while the head 3 traces B to C. The data sampled in the period of t4 to t7 in synchronization 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 reading of data from the tape 1 by the head 3 is performed at t6 to t7 (same for t1 to t2) according to the signal shown in FIG. 5 (h), and t7 to t8 (t2 according to the signal shown in FIG. 5 (i). The signal processing opposite to that at the time of recording is performed from ~ t3). That is, error correction is performed during this period, and then t8 is applied in accordance with the signal shown in FIG. 5 (j).
The playback audio signal is output at ~ t9 (t3 ~ t6). Of course, the reproducing operation by the head 4 is performed with a phase difference of 180 ° from the above operation, and a continuous reproducing audio signal can be obtained by this.

Also for other regions CH3 to CH6, PG (a) is set to n × 36 °.
It goes without saying that the recording and reproducing operations described above may be performed based on the phase shift, and this does not depend on the tape running direction.

In this way, the VTR can be used as an audio-only device for multiple channels. The problem with such a multi-channel audio-only device is that it is difficult to understand the usage status of each channel due to the division of multiple channels.

<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 or reproducing 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 by using 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. Reference numeral 12 is a rotation detector of the flywheel 14 of the capstan 13, and the rotation detector 12
Is also supplied to the motor control circuit 15 to control 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 generation circuit 16 and the gate pulse generation 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 which shows the recording / reproducing timing of each area | region CH1-CH6, respectively. 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, operation modes 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 based on the area designation data for each of the head 3 and the head 4 as shown in the above-mentioned window pulse (FIGS. 7B to 7G). To be done. 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 21i 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 added by the adder 24 to 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. The output of the adder 24 is appropriately gated by the gate circuit 20 as described above, and is written in the area CH2 by the heads 3 and 4.

During reproduction, the reproduction signals of the heads 3 and 4 are also supplied to the low pulse filter (LPF) 25 and the PCM audio circuit 22 via the gate circuit 20 by the window pulse (c). PCM
In the audio circuit 22, signal processing such as error correction, time axis expansion, digital-analog conversion and the like is performed contrary to recording, and a reproduced analog audio signal is output from the terminal 21o.

The LPF 25 separates the tracking pilot signal and supplies it to the ATF circuit 26. The ATF circuit 26 is a circuit for obtaining a tracking error signal by the well-known 4-frequency system,
It is well known that the reproduced pilot signal for tracking and the pilot signal generated by the pilot signal generating circuit 23 at the same rotation as during recording are used. The tracking error signal thus obtained is supplied to the motor control circuit 15, and the running of the tape 1 during reproduction is controlled via the capstan 13 to perform tracking control.

On the other hand, the gate circuit 27 is controlled by the gate pulse output from the gate pulse generation circuit 17 and shown in FIGS. 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 heads through the gate circuit 27.
Terminals to which the reproduced signals of 3, 4 are supplied, 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 comprises a discriminating circuit 37 for the A head 3, a discriminating circuit 38 for the B head 4, and a decoder 47 for serial-parallel converting the outputs of them and outputting them as 6-bit data. Since the determination circuits 37 and 38 have the same configuration diagram, 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, and the areas CH1, CH4 and CH are
It is assumed that 6 is a recorded area 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) to (i). That is, if Δt is a minute time (1/30 × 1/2 × 1/5 × 1 / 10sec), CH1
When the time constant is expressed by an equation, it corresponds to the N-th channel counted from, Δt (sec) when N = 1, and N-2 when N is 2 or more.
It becomes / 300 + Δt (sec).

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 1/60 ×
It is about 1/5 x 4/5 sec. This pulse (Fig. 9 (j)-
According to (o), the detection can be performed at the center position of each area. All the outputs of the monomulti group 43 are supplied to the OR gate 44, and these are AND gates as sampling pulses.
While being supplied to 45, it is also used as a clock for serial-parallel conversion of the decoder 47.

In the AND gate 45, the logical product of the output of the OR gate 44 and the above-mentioned gate pulse (shown in FIG. 9 (c)) is obtained, and the recording status is discriminated only in the area other than the reproduction area.

On the other hand, the reproduced signal is supplied to the LPF 39, and the tracking pilot signal components f ₁ , f ₂ , f ₃ , f ₄ are separated. LPF39
The output (shown in FIG. 9 (g)) 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
It is shown in FIG. This signal passes through the decoder 47 and is output as parallel data corresponding to each area from the terminals 48 to
It is output from 53.

That is, the output signals from the terminals 48 to 53 are H when the areas CH1 to CH6 have been recorded, and L when they have not been recorded. These parallel data are supplied to a display unit 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 embodiment as described above, it is possible to simultaneously discriminate the recording status of each area which has been made into multiple channels.

The above example is an example in the case of considering an audio exclusive device, and in the case of an audio exclusive tape recorder, the recording status of each area can be determined by the above embodiment. On the other hand, next, by using a recording format as shown in FIG. 2, it is also used as a VTR, and the audio area 6 in FIG.
And a video-audio dual tape recorder in which the area CH1 in FIG. 4 has the same format. It is assumed that the tape 1 to be used has already been recorded as shown in FIG. 2 when the audio signal is independently recorded in the area CH5 according to the recording pattern as shown in FIG. At this time, of course, since the area CH5 is independently erased and the audio signal is recorded, the tracking pilot signal superimposed on the video signal is the area CH2,
It remains in CH3, CH4 and CH6.

FIG. 10 is a diagram showing a concrete example of the area discriminating circuit 28 in FIG. 6 in consideration of this fact. In FIG. 10, the same components as those in FIG. Is omitted.

The BPF67 is for detecting the color subcarrier of the video signal included in the reproduced signal. If the video signal is recorded by the so-called low frequency conversion method, the pass band is 600 to 800 KHz.
It is set to a degree. The heads 3 and 4 are set to have an azimuth angle of about 600 to 800 KHz, which has no effect.

The low-frequency subcarrier component detected by the BPF 67 is detected by the detection circuit and then supplied to the comparison circuit 69 to be compared with the reference voltage. 63 and 64 are variable resistors, and 65 and 66 are fixed resistors, which form a pair of voltage dividers and divide the voltage indicated by Vref ′ in the figure. These supply different reference voltages to the comparison circuits 41 and 69 so as to compensate for the difference in recording level between the tracking pilot signal and the low frequency conversion color subcarrier.

Now, when the tracking pilot signal and the color subcarrier are detected from a certain area, it is determined that the PCM audio signal is not recorded, and when the tracking pilot signal is detected but the color subcarrier is not detected, the PCM audio signal is detected. It is determined that the signal is recorded in the area. Therefore, the output of the logic gate 70 indicates the recording status of the PCM audio signal in each area in a time division manner.
Similar to the example shown in the figure, it is output from the terminals 48 to 53 as parallel data. The circuit 61 and the circuit 62 have the same configuration.

In the embodiment of FIG. 10, it is determined that the video signal is recorded by detecting the color subcarrier, but if the video signal is unique, other frequency components may be detected. It is also possible to configure.

Further, in the above-described two embodiments, 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 at the time of high-speed tape feeding. Needless to say. If the magnetic tape 1 can be traced by the rotary heads 3 and 4, the recording status can be immediately discriminated.

<Invention of Effects> As described above, according to the present invention, the recording status of the entire area can be immediately grasped by using only the output of the rotary head, and a rotary head type recording or reproducing apparatus which is extremely convenient for the user can be obtained. It is a thing.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional VTR tape running system, 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 running 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 concrete example of the area discrimination circuit in FIG. FIG. 9 is a diagram showing an example, FIG. 9 is a timing chart for explaining the operation timing of each part in FIG. 8, and FIG. 10 is a diagram showing another specific example of the area discrimination circuit in FIG. 1 is a magnetic tape as a recording medium, 3 and 4 are rotary heads, 1
6 is a window pulse generation circuit, 17 is a gate pulse generation circuit, 28 is an area discrimination circuit, 29 is a display, 39 is an LPF for separating a tracking pilot signal, 40 is a detection circuit, 47
Is a decoder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirohisa Takahashi 770 Shimonoge, Takatsu-ku, Kawasaki-shi, Kanagawa Canon Inc. Tamagawa Plant (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 display unit for displaying the discriminative output of the discriminating unit by discriminating the recording state of each area by detecting the presence or absence of the detection output of the detecting unit. Rotating head type recording or reproducing device.