JPH07109677B2 - Recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint of a plurality of inclined tracks in which one piece of information is recorded when another piece of information is recorded. The present invention relates to a recording device that records so as to be in the same state as when continuously recorded.

[Conventional technology]

Generally, in a video tape recorder, when attempting to edit a plurality of pieces of image information so that they are sequentially connected on a single magnetic tape, recording and pausing operations are repeatedly performed as necessary to connect them. Various conditions such as the timing of recording new image information and the recording order of the head tracking control signal must be the same as in the case of continuous recording. If this is not done, there will be a disturbance in the servo operation of the capstan servo system and a disturbance in the reproduced image at the joint of the image information during reproduction.

Therefore, conventionally, when attempting to edit a plurality of pieces of image information so as to sequentially connect them to one magnetic tape, the following is performed, for example, as shown below. When the record button is turned on, the drum motor and capstan motor start rotating with the magnetic tape on which the previous image information is recorded rewound by a predetermined amount,
The reproduction tracking servo is operated and recording of the next image information is started after the just track is established.

By the way, as a reproducing tracking servo method, a plurality of pilot signals having different frequencies are cyclically recorded in a plurality of recording tracks on a magnetic tape on which image information is recorded, and are reproduced together with the image information from the recording track during reproduction. An automatic track following method (ATF method) has been proposed which performs tracking based on a pilot signal.

The method of adopting this ATF method as the method of reproducing tracking servo in the continuous shooting described above is described in, for example, Japanese Patent Laid-Open No. 59-68881.

As a known method of reproducing tracking servo, a CTL pulse (control pulse) recorded along the running direction of the magnetic tape corresponding to a plurality of recording tracks on the magnetic tape on which image information is recorded is well known. ) There is a CTL method that performs tracking servo based on.

[Problems to be solved by the invention]

According to the above-mentioned conventional apparatus, since the start of the continuous shooting recording is premised on the just track in the reproduction tracking servo, there is a problem that the start-up time from the turning on of the recording button to the actual start of the recording is long. is there.
In addition, a reproducing tracking servo circuit is required, which complicates the configuration and increases the cost.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention reproduces a magnetic tape at a traveling speed slower than usual from a state where a magnetic tape on which one piece of information is rewound by a predetermined amount is rewound and is reproduced by a rotating magnetic head. The just-track state is detected from the envelope of the signal, and after the just-track state is detected, recording of other information is started by the rotating magnetic head with the running speed of the magnetic tape set to the normal speed.
For example, the traveling speed slower than usual is a traveling speed of 5/6 of the ordinary speed, and the minimum or maximum point of the envelope of the reproduction output is detected to detect the just-track state.

[Action]

When the magnetic tape is played back at a traveling speed slower than usual, the rotating magnetic head changes its tracking state at a predetermined cycle with respect to the recording track, and the envelope of the reproduction signal changes accordingly. For example, the dust track state can be detected by detecting the minimum or maximum point, and since the running speed of the magnetic tape is set to the normal speed thereafter, the dust track state continues as it is, and other information can be recorded satisfactorily as before. be able to.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. This example is an example applied to a recording apparatus in which four pilot signals f ₁ , f ₂ , f ₃ , f ₄ having different frequencies for tracking servo during reproduction are cyclically recorded on a plurality of inclined tracks. .

In FIG. 1, (1A) and (1B) are rotary magnetic heads having different inclination angles of the gears with respect to the scanning direction, so-called azimuth angles, and are arranged at angular intervals of 180 °. Further, (2) is a magnetic tape, which is slanted around the tape guide drum (3) in an angular range of about 180 ° and made to run. The heads (1A) and (1B) rotate once per frame, the head (1A) scans the magnetic tape (2) in an odd field, and the head (1B) scans the magnetic tape in an even field. (2) is scanned.

Further, in FIG. 1, (4) shows four pilot signals f ₁ and f ₁ with different frequencies for the tracking servo during reproduction.
It is a generator that cyclically generates f ₂ , f ₃ , and f ₄ every one field and is controlled by a system control circuit (hereinafter referred to as syscon) (5). The video signal to be recorded, which will be described later, is an odd field when the pilot signals f ₁ and f ₃ are generated from this generator (4), and an even field when the pilot signals f ₂ and f ₄ are generated. The pilot signal S _P generated by this generator (4)
[F _{1 to} f ₄ ] are supplied to the adder (6).

In FIG. 1, the terminal (7) is supplied with a video signal S _V to be recorded, for example, a composite signal of an FM-modulated luminance signal and a low-frequency-converted carrier color signal.
S _V is supplied to the adder (6). Also this video signal
S _V is supplied to the vertical sync separation circuit (8) to provide the vertical sync signal.
P _V is separated and supplied to the system controller (5).

The composite signal of the video signal S _V and the pilot signal S _P obtained from the adder (6) is supplied to the heads (1A) and (1B) via the recording amplifier (9). Whether the composite signal is output from the recording amplifier (9) is controlled by the syscon (5), that is, the recording timing is the syscon (5).
Controlled by.

Further, head (1A), the reproduced signal from the magnetic tape (2) obtained from (1B) has a center frequency through a playback amplifier (10), for example, a band-pass filter which is the frequency of the pilot signal f ₃ (11 ) Is supplied to the detection circuit (12) for the pilot signal f ₃ and the detection signal S ₃ is supplied to the syscon (5).

The reproduction signal from the reproduction amplifier (10) is supplied to the envelope detection circuit (13), and the envelope output S _E from this detection circuit (13) is supplied to the minimum point detection circuit (14). In this detection circuit (14), the threshold value V _th close to zero is set.
There is set, the envelope output S _E is the threshold V _th
It is output detection signal S _L when the below, the detection signal S _L
Is supplied to the syscon (5).

Further, in FIG. 1, (15) is a drum motor,
It is controlled by the syscon (5) via the drive circuit (16). Further, (17) is a capstan motor, which is controlled by the syscon (5) via the drive circuit (18). Further, (19) is a record button for operating the start of recording.

Consider the case where the record button (19) is turned on at time t ₁ in the above configuration.

First, the drum motor (1 at time t ₂ as shown in FIG. 2 A
The rotation of 5) is started, and the servo is locked at a time point t ₄ as shown in FIG. That is, as described above, the heads (1A) and (1B) rotate once in one frame.

Further, as shown in FIG. 2C, the capstan motor (17) starts to rotate at time t ₃ , and its speed is set to the normal 5/6 speed as shown in FIG. 2D. That is, the magnetic tape (2) is run at a normal speed of 5/6.

Incidentally, although not mentioned above, the magnetic tape (2) is configured to be rewound by a predetermined amount after the recording is completed, and the magnetic tape (2) is stopped in this state. Therefore, at the time of this recording start operation, the heads (1A) and (1B) are placed in a state of scanning the recording track recorded with the video signal which is the previous image information. FIG. 3 shows a recording pattern on the magnetic tape (2), and T _A and T _{B respectively} show recording tracks on which a video signal which is the previous image information is recorded,
The recording track T _A is formed by a head (1A), the recording track T _B is formed by a head (1B), and these recording tracks T _A
T _A and T _B are different recorded azimuths. Also, in these recording tracks T _A and T _B , the pilot signals f ₁ , f ₂ , f ₃ and f ₄ are cyclically recorded together with the video signal as shown in the figure.

If the running speed of the magnetic tape (2) is set to 5/6 of the normal speed,
Heads (1A) and (1B) are recording tracks with a cycle of 6 frames.
The scanning state of T _A and T _B , that is, the tracking state changes.
This means that the last track is the last track in the third frame from the time when the track is the largest.

After the drum motor (15) starts rotating, the detection circuit (1
The envelope output S _E as shown in FIG. _2E is obtained from 3). Then, at time t ₅ , the envelope output S _E becomes smaller than the threshold value V _th of the minimum point detection circuit (14), and the detection signal S _L is supplied from this detection circuit (14) to the syscon (5). Therefore, in the syscon (5), this time point t ₅ is judged to be the time point at which the above-mentioned track deviation is the largest.

Then, the syscon (5) controls the rotation of the capstan motor (17) at the third frame from the time point t ₅ , that is, at the time point t ₆ when it becomes the thrust track, and its speed is the normal speed as shown in FIG. 2D. The speed is set to "1". That is, the magnetic tape (2) is run at a normal speed. Therefore, the state of just track continues. For example, the third
In the figure, when the alternate long and short dash line represents the scanning locus of the head (1A) and the alternate long and two short dash line represents the scanning locus of the head (1B), time t ₅ and
t ₆ is the position of each illustrated time t ₆ thereafter it can be seen that the state of Jiyasutotoratsuku followed.

However this example is intended to record four pilot signals _{f 1, f 2, f 3} , f 4 for tracking servo during reproduction of the recording tracks cyclically, during recording, the pilot signal f ₁ ~ The pilot signal S _P from the generator (4) is controlled so as to maintain the continuity of f ₄ .

That is, from the detection circuit (12), when the head (1A) scans the recorded track T _A of the pilot signal f ₃ after being set to the just track at time t ₆ , as shown in FIG. 2F. A detection signal S ₃ is obtained, which is fed to the syscon (5). Therefore, the generator (4) by the syscon (5)
Is controlled, and the pilot signals f ₄ , f ₁ , and ₁ are sequentially obtained from the next field at which the detection signal S ₃ is obtained as shown in FIG. 2G.
f ₂ , ... Is generated.

In this way, after the pilot signal S _P (f _{1 to} f ₄ ) is controlled so that the continuity is maintained, as shown in FIG. 2H, for example, the pilot signal f ₁ is generated from the generator (4). Once t ₇ to be generated, the system controller (5) a recording amplifier (9) is controlled, the recording to the magnetic tape (2) above is actually started.

As described above, according to this example, since the reproduction tracking servo is not used to set the just track state for starting the continuous shooting recording, the time from the turning on of the recording button to the start of the actual recording is It gets shorter. For example, in the conventional reproduction tracking servo, it takes only a few seconds, but according to this example, it is possible in a few seconds. Also, according to this example, the circuit of the reproducing tracking servo is not required,
The configuration is simple and inexpensive.

In FIG. 1, (20) is a clock detection circuit, and the detection circuit (13) supplies the envelope output S _E to the detection circuit (20) to detect the clock (that is, clogging). . The output of the detection circuit (20) is supplied to the syscon (5).

In the above embodiment, the bandpass filter (1
1), the detection circuit (12) detects the pilot signal f _3, but the detection signal ( ₃ ) is not limited to the pilot signal f ₃ and may be any one of f ₁ , f ₂ , and f ₄ . The point is that after the detection, the generator (4) generates from the next detected pilot signal in the next order. Further, in the above-described embodiment, the speed of the capstan motor (17) is initially set to 5/6 of the normal speed, but the speed is not limited to this and may be, for example, 3/4. In that case, head (1A) (1B)
The recording cycle T _A , T _B scan state change cycle changes. Further, in the above-described embodiment, the minimum point of the envelope output S _E is detected and the subsequent third frame is judged to be in the just-track state, but other points,
For example, the maximum point may be detected, and the just-track state may be determined from this. Although above embodiment is an example of a recording apparatus in which four pilot signals f ₁ ~f ₄ is recorded, CTL for tracking servo during reproduction
The present invention can be similarly applied to a recording device that records pulses in the longitudinal direction of the magnetic tape (2).

〔The invention's effect〕

According to the present invention described above, since the reproduction tracking servo is not used unlike the conventional method for setting the just track state for starting the continuous shooting recording, from the turning on of the recording button to the start of the actual recording. The time can be much shorter than before. Further, according to the present invention, a reproducing tracking servo circuit is not required, and the structure can be simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIGS. 2 and 3 are diagrams for explaining the operation thereof. (1A) and (1B) are rotating magnetic heads, (2) is a magnetic tape, (5) is a system control circuit, (13) is an envelope detection circuit, (14) is a minimum point detection circuit, (1)
5) drum motor, (17) capstan motor, (1
9) is a record button.

Claims (1)

[Claims] 1. A magnetic tape on which one information is recorded on a plurality of inclined tracks by a rotating magnetic head, and another information is recorded on the plurality of inclined tracks by the rotating magnetic head following the one information. In a state where the magnetic tape on which the one information is recorded is rewound by a predetermined amount, the tape is run at a running speed nV (0 <n <1, n is an integer, V is a normal speed, and the tape is moved by the rotary head. Envelope detecting means for reproducing one piece of information and detecting the envelope of the reproduced signal, minimum point detecting means for detecting the minimum point of the detection output of the envelope detecting means, and the tape from the detection output of the minimum point detecting means. And a tape running speed control means for controlling the running speed of the tape. After the minimum point of the envelope is detected, the tape is run at the running speed nV for a predetermined period, and then the running speed is set to V (V is By atmospheric speed) as the rotary magnetic head recording apparatus characterized by starting the recording of the other information.