JPH0614312Y2 - 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, when a control signal is detected, the drum servo and the capstan servo are locked, and then the magnetic tape is reversely run in the opposite direction.

[Conventional technology]

In the recently standardized R-DAT, a magnetic tape is wound around a rotating drum by about 90 degrees, and information is recorded / reproduced by a rotating head. The inclined track is roughly divided into three areas, and the central area P has PCM.
An audio signal is recorded, and predetermined subcode signals are recorded in the areas S ₁ and S ₂ on both sides thereof. As a sub-code signal, for example, a start ID signal is required to be recorded at the beginning of each program for about 9 seconds (about 600 tracks) so that the program can be searched for even at high speed.

[Problems to be solved by the invention]

By the way, when searching for the start ID, the magnetic tape is run (FF) in the forward direction at a speed (for example, 200 times) that is considerably faster than the speed during normal recording / reproduction. Therefore, after the start ID (S-ID) is detected, the magnetic tape runs for a considerable amount and then stops, so that the magnetic tape is temporarily moved in the opposite direction until the start end of the start ID is detected.
It is run (REV MID) at a speed of 0 times. Then, the vehicle again travels in the original direction at the speed at the time of normal recording / reproduction to reproduce (FIG. 6 (a)).

On the other hand, even when the start ID is detected by running the magnetic tape in the reverse direction at high speed (REW), overrun occurs even if a stop command is output when the start ID is detected, so the magnetic tape moves in the opposite direction (forward direction). Run again at speed (FWD
MID), and the start ID is detected again. Then, when the start ID is detected at a medium level, or after slightly traveling in the opposite direction (REVIEW MID) to locate the start ID, the speed is reversed again and switched to the normal recording / reproducing speed ( FIG. 6 (b)).

In this way, when the running speed of the magnetic tape is switched from high speed to medium speed, since the difference is large, the speed of the rotary head (rotary drum) is also switched in order to reproduce the control signal, and the relative speed between the two is kept as constant as possible. Need to be. However, in the conventional device, since the speed is disturbed in the transitional state at the time of this inversion, the start ID signal may be erroneously searched or a search omission may occur.

[Means for solving problems]

In order to solve the above problems, the present invention provides a reproducing means (6) having a rotary drum for rotating a rotary head for reproducing a recording signal recorded on a magnetic tape (1),
A specific control signal (for example, from the reproduced recording signals)
Control signal detecting means (8) for detecting the start ID signal)
And a drum servo means (6) for holding the number of rotations of the rotary drum in the reproducing means constant, and a drum lock detecting means for detecting that the drum servo means is locked and outputting a drum lock detection signal. (9),
Running the magnetic tape (1) in a first direction at a first speed faster than normal speed (for example, by a reel motor), and moving the magnetic tape (1) faster than normal speed, and A traveling unit (2) capable of traveling in a second direction opposite to the first direction (for example, traveling by a capstan and a pinch roller) at a second speed lower than the first speed. And a function of controlling the rotation state of the rotary drum in the reproducing means (6) based on the detected specific control signal, and the magnetic tape (1) is run in the first direction. In this case, when the specific control signal is detected, the number of rotations of the rotary drum is switched, and the traveling means (2) is provided with a traveling control signal for traveling the magnetic tape (1) in the second direction. Out Then, after detecting that the drum servo means (6) is locked by the drum lock detection signal, the control means (3) for outputting a traveling force transmission command signal and the receiving means for receiving the traveling force transmission command signal A traveling force transmitting means (2) for transmitting a traveling force for traveling the magnetic tape (1) in the second direction at a second speed of the traveling means (2) to the magnetic tape (1). To do.

[Action]

 The operation of the present invention will be described with reference to FIG.

The reproducing means (6) has a rotary drum that rotates a rotary head, and reproduces a recording signal recorded on the magnetic tape (1).

The control signal detecting means (8) detects a specific control signal (for example, a start ID signal) from the reproduced recording signal, and the control means (3) outputs a signal indicating the detection.

The drum servo means (6) keeps the number of rotations of the rotary drum in the reproducing means (6) constant.

The drum lock detecting means (9) detects that the drum servo means (6) is locked, and outputs a drum lock detection signal to the control means (3).

The running means (2) has a function of running the magnetic tape (1) in a first direction at a first speed higher than a normal speed by, for example, a reel motor or the like, and, for example, a capstan and a pinch roller. As a result, the magnetic tape (1) is moved at a second speed, which is higher than the normal speed and lower than the first speed, at a second speed opposite to the first direction.
It has the function of running in the direction of.

The control means (3) has a function of controlling the rotation state of the rotary drum in the reproducing means (6) based on the detected specific control signal, and controls the magnetic tape (1) to the first state. In the case of traveling in the first direction at the first speed, when the specific control signal is detected, the rotational speed of the rotary drum is switched, and the magnetic tape (1) is run in the second direction. A traveling control signal for outputting to the traveling means (2), and after detecting that the drum servo means (6) is locked by the drum lock detection signal from the drum lock detecting means (9), traveling Outputs a force transmission command signal.

The traveling force transmission means (2) receives the traveling force transmission command signal output from the control means (3) and moves in the second direction at the second speed of the traveling means (2) to the magnetic tape (1). The traveling force for traveling is transmitted to the magnetic tape (1), and the traveling of the magnetic tape (1) in the second direction at the second speed is started.

With the above operation, after the rotation number of the rotary drum is switched, the magnetic tape (1) is started to run after the rotation is stabilized, so that the specific control signal can be stably detected. You can

〔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 the lock of the capstan servo loop and the drum servo loop, and 10 is a detecting means for detecting the RF signal from the reproduction 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 input means 4 issues a search command for the start ID signal, the control means 3 controls the running means 2 to run the magnetic tape 1 at a higher speed than normal (for example, about 200 times speed) in the forward direction, for example. The reproducing means 6 reproduces the recording signal of the magnetic tape 1. 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. 3 (b): FIG. 3). For convenience, the detection signal is shown when one inclined track is accurately traced). On the other hand, a window pulse (FIG. 3 (c)) synchronized with the head switching pulse (FIG. 3 (a)) output by the traveling means 2 is generated and output by the window pulse generating means 11. The detection means 8 monitors the detection means 10 and the output of the window pulse generation means 11 and reads the reproduction signal only when the level of the RF signal within the window pulse is equal to or higher than a predetermined value. This prevents erroneous detection of noise and the like.

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 in two places (areas S ₁ and S ₂ ) on _one inclined track and about 600 tracks (9 seconds). Although it is possible to output the detection signal immediately when the start ID is detected even once, there is a risk of erroneous 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.

The determination in this case is shown in a flowchart in FIG. 5, for example. That is, first, the data in the buffer memory is initialized and then the subcode data is read. Next, it is determined whether or not the parity of the subcode data in the area S ₁ is correct.

If the parity of the subcode data in the area S ₁ is correct,
Next, the subcode data in the area S ₁ is compared with the data stored in the buffer memory, and when they are equal, the subcode data is determined as correct and is output.

If they are not equal, the subcode data of the area S ₁ is set in the buffer memory, and then it is determined whether the parity of the area S ₂ is correct as in the case where the parity of the area S ₁ is incorrect. When the validity is incorrect, the next subcode data is read. When the parity is correct, the data in the area S ₂ is compared with the data in the buffer memory. When both are equal, the subcode data is confirmed as correct and output. When they are not equal, the data in the area S ₂ is set in the buffer and the next subcode data is read.

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, reverses the magnetic tape at the medium speed of the capstan which has been stopped until then (for example, a speed several ten times higher than that during normal recording and reproduction). The rotation in the direction corresponding to the traveling in the direction is started. 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.

The control means 3 monitors the drum servo and the capstan servo via the detection means 9. When the detection means 9 detects the lock of the drum servo and the capstan servo, the control means 3 controls the traveling means 2 to press the pinch roller to the capstan. As a result, the magnetic tape runs in the opposite direction at medium speed. The above operation is shown in a flowchart of FIG.

While the magnetic tape 1 is running in the reverse direction at medium speed, the detecting means 8 monitors the start ID signal in the same manner as described above. When the start ID is detected, the control means 3 controls the running means 2 to stop the medium speed mode, and the magnetic tape 1
The capstan servo is switched so as to drive in the normal direction at the speed of normal recording and reproduction. At this time, since the rotary head has already rotated at the same speed as in the case of normal recording / reproducing, the drum servo remains unchanged.

When the detection means 9 detects the lock of the capstan servo (the drum servo remains locked), the control means 3 presses the pinch roller onto the capstan. As a result, the reproduction of the program having the retrieved start ID signal at the beginning is started.

The timing of the above search operation is schematically illustrated as a fourth example.
As shown in the figure. That is, when the start ID is detected during high speed (FF) traveling or medium speed traveling, the system waits until the capstan servo or the drum servo locks in the subsequent section A, and presses the pinch roller in the section B after locking. , Move to the next medium speed mode or playback mode.

Although the present invention has been described by taking the case of searching for the start ID as an example, the present invention can be applied to the case of searching for other control signals such as the skip ID.

〔effect〕

As described above, according to the present invention, a specific control signal (for example, a start ID signal) recorded on a magnetic tape is used.
In the case of detecting the second tape of the magnetic tape, after the drum lock detecting means detects that the drum servo means is locked, that is, after the rotation of the rotary head in the reproducing means reaches a predetermined rotational speed and stabilizes. Since it is controlled to start traveling at the second speed in the direction,
Even after switching the running speed or running direction of the magnetic tape, it becomes possible to correctly search for the specific control signal,
It is possible to prevent erroneous detection and malfunction.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus of the present invention, and FIG.
FIG. 5 and FIG. 5 are flowcharts thereof, FIGS. 3 and 4 are timing charts thereof, and FIG. 6 is an explanatory diagram of the search operation. 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) Yoshiki Furuta, 4,2610 Hanazono, Tokorozawa, Saitama Prefecture, Tokorozawa Plant, Pioneer Co., Ltd. (72) Shinichi Yamamizaka, 2626, Hanazono, Tokorozawa, Saitama Pioneer In Tokorozawa Factory (72) Inventor Naoto Arifu 42610 Hanazono, Tokorozawa City, Saitama Pioneer Co., Ltd. In Tokorozawa Factory (56) Reference JP-A-58-196645 (JP, A) JP-A-61-126649 (JP, A) JP45-36064 (JP, B1) JP55-803 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A reproducing means (6) having a rotary drum for rotating a rotary head for reproducing a recording signal recorded on a magnetic tape (1), and a specific control signal from the reproduced recording signal. A control signal detecting means (8) for detecting, a drum servo means (6) for keeping the number of rotations of the rotary drum in the reproducing means constant, and a lock of the drum servo means are detected to detect a drum lock. A drum lock detecting means (9) for outputting a detection signal; running the magnetic tape (1) in a first direction at a first speed higher than a normal speed; Traveling means (2) capable of traveling in a second direction opposite to the first direction at a second speed higher than the speed and slower than the first speed; and the detected specific Control signal The reproducing device (6) has a function of controlling the rotating state of the rotating drum based on the reproducing means (6), and detects the specific control signal when the magnetic tape (1) is running in the first direction. At this time, the number of rotations of the rotary drum is switched, a running control signal for running the magnetic tape (1) in the second direction is output to the running means (2), and the drum lock detection signal causes the drum to be detected. After detecting that the servo means (6) has locked, a control means (3) that outputs a traveling force transmission command signal, and a second speed of the traveling means (2) that receives the traveling force transmission command signal. And a traveling force transmitting means (2) for transmitting a traveling force for traveling the magnetic tape (1) in the second direction to the magnetic tape (1).