JPH0614274Y2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a magnetic recording / reproducing apparatus represented by an R-DAT, an 8 mm video tape recorder and the like.

[Outline of device]

In the present invention, the blank portion of the magnetic tape is searched using the RF signal, the cue signal and the silent portion.

[Conventional technology]

In the conventional video tape recorder, the blank portion of the magnetic tape is detected by using the RF signal. That is, for example, as shown in FIG. 4, the start end (B
4 programs are recorded sequentially from OT), and non-signal parts b ₁ , b ₂ , b ₃ are formed between the programs, and
No signal part (blank part) b behind the th program
₄ is formed. In such a case, the magnetic tape is fast-forwarded in the end (EOT) direction, and the traveling is stopped when the RF signal disappears for a predetermined time or longer. Then, if necessary, run in the opposite direction according to the amount of overrun, and R
The end portion E of the F signal is searched.

[Problems to be solved by the invention]

By the way, in the recently standardized R-DAT and multi-track 8 mm video tape recorders, audio signals are digitized and recorded on a magnetic tape.
Even if the audio signal is silent, it may be recorded as a zero-level signal to form a track, for example. Since an RF signal exists in such a silent portion, it is difficult to detect a substantial blank portion (the beginning of the blank portion) only by detecting the presence or absence of the RF signal.

[Means for solving problems]

The present invention is, in a magnetic recording / reproducing apparatus, a traveling means for traveling a magnetic tape at a speed faster than a normal recording / reproducing operation, a reproducing means for reproducing a recording signal from the magnetic tape, and an RF of a reproducing signal output by the reproducing means. A first detecting means for detecting a signal, a second detecting means for detecting a cue signal from the reproduced signal, a third detecting means for detecting a silent portion of the reproduced signal, and a magnetic tape terminating direction. When the first detection means detects that the RF signal has disappeared during traveling in the end direction, the magnetic tape is reversed in the starting end direction and the traveling in the starting end direction is performed. In the case where the second detecting means detects the cueing signal in the meantime, the magnetic tape is reversed again in the terminal direction, and the third detecting means detects the silent portion during the reverse running. To the magnetic Characterized in that it and a control means for stopping up.

[Action]

The first detection means R of the magnetic tape that has run toward the end is R.
When it is detected that the F signal has disappeared, the vehicle is reversed. When the second detecting means detects the cueing signal during reverse running, the magnetic tape is reversed again and the silent portion is detected by the third detecting means.

〔Example〕

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus of the present invention. In the figure, reference numeral 1 is a magnetic tape, which is run by a running means 2 including a capstan, a pinch roller, a reel motor and the like (not shown). The traveling means 2 has a capstan servo circuit for rotating the capstan at a predetermined speed. Reference numeral 3 denotes a control means such as a microcomputer, which executes a predetermined command input from the input means 4 such as a switch and a keyboard. Numerals 5 and 6 are a recording means and a reproducing means for recording and reproducing a signal on the magnetic tape 1, and include a rotary head which is switched at the time of recording and reproducing, and a drum servo circuit which controls the rotation of a rotary drum for rotating the rotary head. Contains. Reference numeral 7 is a generating means for generating a start ID signal as a control signal, and 8
Is a detecting means for detecting the start ID signal from the reproduction signal. Reference numeral 9 is a detecting means for detecting a silent portion (voiced portion) of the reproduced signal, and 10 is a detecting means for detecting an RF signal from the reproduced signal. Reference numeral 11 is a window pulse generating means, which generates and outputs a window pulse in synchronization with a head switching pulse which the traveling means 2 outputs in synchronization with the rotational position of the rotary drum (rotary head).

However, when the blank means is instructed from the input means 4, the control means 3 controls the running means 2 and the magnetic tape 1
Is run (FF) in a forward direction at a higher speed than usual (for example, about 200 times faster), and the magnetic tape 1 is applied to the reproducing means 6.
The recorded signal of is reproduced. The detection means 10 detects the envelope of the RF signal from the reproduction signal output by the reproduction means 6, and outputs the detection signal when the level is equal to or higher than a predetermined reference value (Fig. 2 (b): in the figure). For convenience, the detection signal is shown when one inclined track is accurately traced). On the other hand, a window pulse (FIG. 2 (C)) synchronized with the head switching pulse (FIG. 2 (a)) output by the traveling means 2 is generated by the window pulse generation means 11,
Is output. The control means 3 monitors the outputs of the detection means 10 and the window pulse generation means 11 and detects when the level of the RF signal is equal to or higher than a predetermined value within the window pulse. This prevents erroneous detection of noise and the like.

The control means 3 has R for a predetermined time or more within the wind pulse.
When it is detected that the F signal has disappeared (the number of fields in which the RF signal has not been detected has exceeded a predetermined value), the traveling means 2 is controlled and the magnetic tape 1 is moved in the opposite direction at a high speed (200
The reverse traveling (REW) is performed at double speed, and the detection means 8 is controlled to detect the start ID signal.

The detection means 8 outputs a detection signal to the control means 3 when detecting the start ID from the read subcode data.

The start ID is recorded at two positions (areas S ₁ and S ₂ ) on _one inclined track and about 600 tracks (9 seconds). It is possible to output the detection signal immediately when the start ID is detected even once.
There is also a risk of false detection due to noise or the like. Therefore, it is preferable to output the detection signal when the start ID is detected at least twice.

Also in this case, the control means 3 controls the detection means 8 to read the subcode data only when the RF signal is present in the window pulse.

When the start ID detection signal is input, the control means 3 sets the medium speed mode and controls the traveling means 2 and the reproducing means 6. At this time, the running means 2 stops the high-speed running by driving the reel of the magnetic tape, and at the same time, starts the rotation of the capstan which has been stopped until then (medium speed of ten times higher than that during normal recording and reproduction). On the other hand, the reproducing means 6 switches the rotation speed of the rotary drum from high speed to medium speed. That is, when the magnetic tape is running at a high speed, the rotary head is, for example, 3000 rpm (FF) or 1000 rpm (REW).
At the time of rotation, the medium speed is switched to the same speed (for example, 2000 rpm) as in the normal recording and reproduction.

While the magnetic tape 1 is running in the reverse direction at medium speed, the detecting means 9 monitors the reproduced signal and detects the silent portion. Here, the silent part means a part where the level of the audio signal is equal to or lower than a predetermined value. Therefore, even if the RF signal is present, a portion where the level of the reproduced audio data is substantially zero is detected as a silent portion. The control means 3 monitors the silent portion in the presence of the RF signal in the wind pulse, and controls the traveling means 2 when the length of the silent portion exceeds a predetermined value,
The magnetic tape 1 is stopped.

That is, for example, as shown in FIG. 3, when there is a silent part a _{1 to} a _{4 at} the end of each program and a silent part b _{1 to} b ₄ following it, the last (4th) program The end of the sound part (starting end of the silent part) E ₁ is searched, and the magnetic tape is stopped at a position after running for a predetermined time (distance). Therefore, even if the recording time of the zero-level signal (silent portion a ₄ ) is long, the vicinity of the end portion E ₁ of the voiced portion is searched and the next program can be recorded from there.

〔effect〕

As described above, in the magnetic recording / reproducing apparatus according to the present invention, the traveling means for traveling the magnetic tape at a higher speed than the normal recording / reproducing operation, the reproducing means for reproducing the recording signal from the magnetic tape, and the reproducing operation output by the reproducing means. First detecting means for detecting an RF signal of the signal, second detecting means for detecting a cue signal from the reproduced signal, third detecting means for detecting a silent portion of the reproduced signal, and the magnetic tape In the end direction, and when the first detecting means detects that the RF signal disappears during the travel in the end direction, the magnetic tape is reversely run in the start direction, and in the start direction. When the second detecting means detects the cueing signal during traveling, the magnetic tape is reversed again in the terminal direction, and the third detecting means removes the silent portion during the reverse traveling. When detected A control means for stopping the serial magnetic tape is provided with the can search quickly and accurately regardless blank portion to the length of the silent portions.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus of the present invention, and FIG.
FIG. 4 is a timing chart thereof, FIG. 3 is an illustration of the search operation, and FIG. 4 is an illustration of the search operation of the conventional device. 1 ... magnetic tape 2 ... running means 3 ... control means 4 ... input means 5 ... recording means 6 ... reproducing means 7 ... generating means 8, 9, 10 ... detecting means 11 ... wind pulse generation means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masafumi Tanabe 4-2610 Hanazono, Tokorozawa-shi, Saitama Pioneer Co., Ltd. Tokorozawa Plant (72) Yoshiki Furuta 4-2610 Hanazono, Tokorozawa-shi, Saitama Pioneer Co., Ltd. Tokorozawa Plant (72) Inventor Naoto Arifuku 42610 Hanazono, Tokorozawa City, Saitama Pioneer Co., Ltd. Tokorozawa Plant (56) References JP 59-198551 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A traveling means for traveling a magnetic tape at a speed higher than that during normal recording / reproducing, a reproducing means for reproducing a recording signal from the magnetic tape, and an RF signal of a reproducing signal outputted by the reproducing means. First detection means, second detection means for detecting a cue signal from the reproduction signal, third detection means for detecting a silent portion of the reproduction signal, and running the magnetic tape in the end direction, When the first detecting means detects that the RF signal has disappeared during the running in the end direction, the magnetic tape is reversed and run in the starting end direction, and the running in the starting end direction causes the magnetic tape to reversely run. When the second detecting means detects the cueing signal, the magnetic tape is reversely run again toward the end direction, and the magnetic tape is detected when the third detecting means detects the silent portion during the reverse running. Control to stop Magnetic recording and reproducing apparatus characterized by comprising a means.