JPH07254193A - Information reproducing device - Google Patents

Abstract

PURPOSE:To reduce a load on a capstan motor during intermittent reproducing or frame feeding and to stably detect the phase of a magnetic tape and a transfer speed at the time of intermittent reproducing. CONSTITUTION:As a detecting head for a control signal, a ring type head is replaced by a control head 20 comprising a magneto resistance effect element. When a magnetic tape 1 is intermittently traveled by one frame unit, a tape position is detected by a tape position calculating circuit 22 and a tape driving control circuit 23 gives a smoothly changing torque control signal to a capstan motor 10. The transfer of the magnetic tape 1 is stopped in a place where the phases of the scanning positions of a recording track and still reproduction are matched with each other and a video signal is reproduced with herical scanning of magnetic heads 5a and 5b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reproducing apparatus having a function of intermittent reproduction of magnetic tape.

[0002]

2. Description of the Related Art In recent years, information reproducing devices (magnetic recording / reproducing devices) using rotary heads have been used in video tape recorders, digital audio tape recorders, etc., and demands for higher recording density and higher accuracy have been increasing in recent years. It is increasing. An example of a conventional information reproducing apparatus will be described by taking the VHS system as an example with reference to the drawings.

FIG. 6 is a block diagram centering on a magnetic tape running mechanism of a conventional information reproducing apparatus. In this figure, the magnetic tape 1 is wound around a tape reel 2a on the supply side and a tape reel 2b on the take-up side, and left and right guide posts 3a, 3b.
Is guided to the drum 4. The drum 4 has a plurality of rotating magnetic heads (hereinafter referred to as magnetic heads) 5 (5a,
5b) is attached and the magnetic tape 1 is helically scanned. A part of the head switching signal generating circuit 6 is attached to the drum 4, and the head switching signal of the magnetic head 5 is output.

A fixed head 7, a capstan 8, a pinch roller 9 and the like are provided on the transfer path of the magnetic tape 1. The fixed head 7 is composed of a ring head, and has a control signal recorded along the edge of the magnetic tape 1,
A magnetic head for detecting a voice signal. Fixed head 7
Is fixed between the guide post 3b and the tape reel 2b. The capstan 8 is attached to the shaft of a capstan motor 10, and is pressed against a movable pinch roller 9 to drive the magnetic tape 1 in various running modes. The capstan motor 10 has a capstan FG10.
a is attached and generates a pulse signal according to the rotation of the capstan 10.

On the other hand, a drum rotation drive circuit 11, a tape phase calculation circuit 12, and a tape drive control circuit 13 are provided as circuit blocks for controlling the running mechanism of the magnetic tape 1. The drum rotation drive circuit 11 rotates the drum 4 at a constant speed, and synchronizes with the signal from the drum FG (not shown) attached to the drum 4 to synchronize the magnetic head 5 with the magnetic head 5.
Is rotated at a constant speed by the FG servo. The tape phase calculation circuit 12 receives a control signal from the fixed head 7, a switching signal from the head switching signal generation circuit 6, and a capstan FG 10.
It is a circuit for calculating the phase of the magnetic head 5 with respect to the recording track of the magnetic tape 1 by inputting the rotation pulses of a respectively. The tape drive control circuit 13 is a tape phase calculation circuit 12
When a tape phase signal is given from the circuit, it is a circuit which outputs a torque control signal (driving torque) for rotational drive to the capstan motor 10 to align the positions of the magnetic head 5 and the recording track with a predetermined phase.

FIG. 7 is a diagram for explaining the operation of the information reproducing apparatus in the conventional intermittent reproduction. 7A shows the drive torque of the capstan motor 10, FIG. 7B shows the head switching signal generated by the head switching signal generation circuit 6, and FIG. 7C shows the control signal output from the fixed head 7. ing. Further, in FIG. 7, a to h are symbols showing the operation procedure, and T1 to T3 in FIG. 7 (a) are capstan motor 10
Drive torque values, and t1, t2, and t3 indicate elapsed time.

FIG. 8 is an explanatory diagram showing the relationship between the recording track of the magnetic tape 1 and the scanning locus of the magnetic head 5. Tracks W1 to W3 shown by solid lines are recording tracks recorded in the standard mode, and track R2 shown by a broken line is a scanning locus of the magnetic head 5 at the time of still reproduction. In still reproduction, the drum 4 rotates at a constant speed, but the magnetic tape 1 is not transferred, so that the scanning locus of the magnetic head 5 is inclined more than the recording track. Then, the position where the magnetic head 5 starts scanning on the magnetic tape 1 and the scanning start position of the already recorded track S1 are displaced by the distance L (phase).

In the information reproducing apparatus configured as described above, the operations during normal reproduction, intermittent reproduction and special reproduction will be described respectively. At the time of normal reproduction, first, the fixed head 7 detects the control signal recorded on the magnetic tape 1.
Then, the tape drive control circuit 13 causes the control signal recorded at a constant pitch to be reproduced at a constant cycle.
The rotation speed of the capstan motor 10 is controlled. Further, the drum rotation drive circuit 11 drives the drum 4 at a constant speed regardless of the type of reproduction mode, and rotates the magnetic head 5 at a constant speed.

Next, the tape drive control circuit 13 uses the output signal of the tape phase calculation circuit 12 to track W1 in FIG.
The rotational phase of the capstan motor 10 is controlled so that the magnetic heads 5a and 5b accurately scan (trace) on W3 to align the scanning tracks of the magnetic heads 5a and 5b.
Thus, the recording tracks W1 to W3 ... Which are adjacent to each other
Are sequentially scanned by the magnetic heads 5a and 5b, and an image is reproduced at the same speed as during recording.

Next, the operation of the intermittent reproduction will be described with reference to FIGS.
The procedure will be described with reference to h. Intermittent feed is one frame,
That is, it means the magnetic tape feeding for two tracks, and the still reproduction is performed thereafter. a. First, the drum rotation drive circuit 11 rotates the drum 4 at a constant speed. From the head switching signal generation circuit 6 to FIG.
A head switching signal as shown in (b) is detected. During this time, the cap stun motor 10 is stopped. b. Next, after the head switching signal is detected and time t1 has elapsed, the tape drive control circuit 13 accelerates the capstan motor 10 with a constant drive torque T1. c. Then, after a certain period of time, the drive torque of the capstan motor 10 is reduced to substantially zero, and the capstan 8 is rotated at the set speed v1 (constant). d. The fixed head 7 detects a pulsed control signal as shown in FIG. e. After the time t2 has elapsed since the control signal was detected,
The tape drive control circuit 13 brakes the capstan motor 10 with a constant braking torque T2. f. The braking torque is reduced to T3 after a lapse of time t3 from the start of applying the brake. g. The tape drive control circuit 13 is a capstan FG 10a.
Confirm that the rotation of the capstan shaft 8 is reversed from the signal of. h. A slight forward drive torque is applied to the capstan motor 8 for a certain period of time to stop the transfer of the magnetic tape 1.

The set speed v1 is set to a value sufficient to obtain a control signal, and torques T1, T2, T
3, and the elapsed times t1, t2, t3 must be set so that the feeding amount of the magnetic tape 1 is one frame.

As shown in FIG. 8, the magnetic head 5 traces as many portions of the recorded track W2 as possible, and the magnetic tape 1 is scanned at the normal scanning position so that the reproduction level of the recording signal can be sufficiently secured. The point is offset by a distance L compared to the time of reproduction. And so that the control signal can be detected in the constant speed section of the magnetic tape 1,
The moving distance of the magnetic tape 1 is secured, and the stop position of the magnetic tape 1 is shifted by the X value (deviation between the video signal track and the audio track) of the magnetic tape 1 at time t2. In this way, the intermittent feeding operation for one frame is completed.

Next, special reproduction will be described. During special reproduction, the video signal is reproduced while the magnetic tape 1 is transferred at a transfer speed different from that of normal reproduction. In this case, the tape drive speed is controlled by the tape drive control circuit 13 so that the number of rotations detected by the capstan FG 10a becomes constant per unit time. Next, the rotary magnetic head 5 is rotated at the same number of rotations as in the normal reproduction. The rotation drive control of the drum 4 is performed by the drum rotation drive circuit 11 using the drum FG.
The angle at which the magnetic head 5 obliquely traces the magnetic tape 1 differs depending on the transfer speed of the magnetic tape 1. Therefore, it is necessary to shift the position where the magnetic head 5 starts scanning with respect to the recorded track so that the magnetic head 5 traces as many portions of the track as recorded on the magnetic tape 1.

The distance L to be shifted at the scanning start point is set individually for each tape transfer speed, and the tape drive control circuit 13 controls the distance L to a predetermined value. Fixed head 7
The tape phase calculation circuit 12 can calculate the shift amount by counting the rotation pulse of the capstan FG 10a until the change point of the head switching signal is input after the control signal is input by.

In the case of double speed reproduction, the tape phase calculation circuit 12 detects the scanning position of the magnetic head 5 and the recording track of the magnetic tape 1 so that the magnetic head 5 traces as much of the recording tracks W1, W2, ... Set the phase of. The head switching signal of the magnetic heads 5a and 5b is detected by the head switching signal generating circuit 6 as in the normal reproduction.

On the other hand, in the case of slow reproduction, the relative speed between the magnetic tape 1 and the fixed head 7 becomes small. Therefore, the output of the reproduction signal of the fixed head 7 proportional to the change of the magnetic flux recorded on the control track of the magnetic tape 1 becomes small. Therefore, the tracks W1 to W1 recorded on the magnetic tape 1 are
With respect to W3, it becomes difficult to accurately detect the amount of deviation from the position where the magnetic head 5 starts scanning the track.

[0017]

However, in the conventional information reproducing apparatus, since the ring head is used as the fixed head 7 for detecting the control signal, particularly in the case of intermittent feeding where the relative speed to the magnetic tape 1 is small, The control signal could not be obtained stably during slow playback. Therefore, the position of the magnetic tape 1 with respect to the magnetic head 5 and the transfer speed of the magnetic tape 1 may not be accurately detected.

Therefore, in the case of intermittent feeding of the magnetic tape 1, the control signal is detected by increasing the rotation of the capstan motor 10 from the stopped state to increase the relative speed between the fixed head 7 and the magnetic tape 1. Making it easier.
In this way, a pulsed control signal can be obtained even if the fixed head 7 is a ring head.

Next, the position (phase) of the magnetic tape 1 is detected by the control signal of the obtained control track, and the capstan motor 10 is moved from that position to a preset position by the time, torque and rotation angle. By controlling, the magnetic tape 1 was transferred to the target position. Therefore, when slippage occurs between the magnetic tape 1 and the capstan 8, or when the magnetic tape 1 expands or contracts,
When the movement amount of the magnetic tape 1 per frame changes, it becomes difficult to intermittently transfer the magnetic tape 1 to the target position.

Even when the feeding amount of the magnetic tape 1 per frame is short, it is necessary to rapidly accelerate the magnetic tape 1 to a speed at which the control signal can be detected with a sufficient amplitude. In this case, there is no choice but to increase the starting torque of the capstan motor 10, which causes a problem of putting a load on the magnetic tape 1. On the other hand, in the case of slow reproduction, the control signal with high positioning accuracy is not reproduced from the fixed head 7 at a certain tape transfer speed or less. Therefore, it becomes difficult to detect the position of the magnetic tape 1, and the magnetic tape 1 cannot be stably transferred. Therefore, when the information reproducing apparatus is specially reproduced, the lower limit of the transfer speed of the magnetic tape 1 is naturally limited.

The present invention has been made in view of the above-mentioned problems of the prior art, and aims to improve the accuracy of tape position adjustment during intermittent feeding of a magnetic tape, reduce the load on the magnetic tape, and perform slow reproduction. It is an object of the present invention to realize an information reproducing apparatus which can set the transfer speed of the magnetic tape at that time lower than that of the conventional one and realize stable intermittent reproduction and slow reproduction.

[0022]

According to the invention of claim 1 of the present application, when recording a magnetic tape having a control track on which a control signal is recorded at a constant pitch and a video signal track on which a video signal is recorded, And a rotary head that has a normal reproduction mode for reproducing at the same transfer speed and a still reproduction mode for reproducing the same video signal by stopping the transfer of the magnetic tape, and is mounted on a rotary drum and records and reproduces a signal on a video signal track. , Drum rotation driving means for rotating the rotating drum at a constant speed, head switching signal generating means for generating a switching signal for the rotating head, and magnetic tape wound around the rotating drum between the supply reel and the take-up reel. The capstan motor is attached to a tape transfer means including a capstan motor and a pinch roller, and is attached to a rotation system of the capstan motor. An information reproducing device including a capstan pulse generating means for generating a rotation pulse according to the rotation of a magnetic tape, comprising a fixed control head composed of a magnetoresistive element for detecting a control signal of a magnetic tape, and a head switching signal generation. The switching signal of the means, the control signal of the control head, and the rotation pulse of the capstan pulse generating means are respectively input, and the distance difference between the track scanning start position of the rotation head and the recording start position of the recording track of the magnetic tape is detected as the tape position. , A tape position calculating means for calculating the tape target transfer amount at the time of minute feeding from the current tape position, and for transferring the magnetic tape at a set speed so that the tape position output from the tape position calculating means becomes a predetermined value. For controlling and transporting magnetic tape in at least still playback mode It is characterized in that it comprises a tape drive control means for providing a motion control signal to the tape transport means.

According to the invention of claim 3 of the present application, a magnetic tape having a control track on which a control signal is recorded at a fixed pitch and a video signal track on which a video signal is recorded is reproduced at the same transfer speed as that at the time of recording. It has the functions of normal playback mode, still playback mode that stops the transfer of the magnetic tape and plays back the same video signal, and special playback mode that runs the magnetic tape at a transfer speed different from that during recording and plays back the video signal. A rotary head mounted on the drum for recording and reproducing a signal on a video signal track, a drum rotation driving means for rotating the rotary drum at a constant speed, a head switching signal generating means for generating a switching signal for the rotary head, and a rotary drum. A taper including a capstan motor and a pinch roller for transferring a wound magnetic tape between a supply reel and a take-up reel. An information reproducing apparatus including a transfer means and a capstan pulse generating means which is attached to a rotation system of a capstan motor and generates a rotation pulse according to the rotation of the capstan motor. , A fixed control head for detecting the control signal of the control head, a switching signal of the head switching signal generation means, a control signal of the control head, and a rotation pulse of the capstan pulse generation means are respectively input, and the track scanning start position of the rotation head and the magnetic tape A tape phase calculating means for detecting a distance difference between recording start positions of recording tracks as a tape phase, a tape transfer speed detecting means for detecting a tape transfer speed when a rotation pulse of a capstan pulse generating means is inputted, and a tape transfer speed detecting means. Refer to the speed signal output from the Tape at a set speed, while controlling the tape phase output from the tape phase calculating means to be a predetermined value, a drive control signal for transferring the magnetic tape in a special reproduction mode including at least slow reproduction is recorded on the tape. And a tape drive control means provided to the transfer means.

[0024]

According to the inventions of claims 1 and 2 having the above characteristics, when the magnetic tape is driven in the still reproduction mode to reproduce the video signal, the tape position calculating means is the control signal of the control head, The rotation pulse of the capstan pulse generating means and the switching signal of the head switching signal generating means are input respectively, and the tape transfer amount from the current stop position to the target position of the track is calculated. Next, the tape drive control means performs position control so that the tape position output from the tape position calculation means becomes a predetermined value, and transfers the magnetic tape within several track intervals. In this way, the same frame can be intermittently reproduced in still mode.

According to the invention of claim 3 of the present application, when the magnetic tape is driven in the special reproduction mode to reproduce the video signal, the tape drive control means refers to the signal output from the tape transfer speed detection means. , Transfer the magnetic tape at the set speed. The tape phase calculating means inputs the control signal of the control head, the rotation pulse of the capstan pulse generating means, and the switching signal of the head switching generating means to detect the tape phase. Next, the tape drive control means performs phase control so that the locus of the scanning track with respect to the recording track becomes the maximum of the reproduction output. In this way, stable tape transfer speed control is performed even during slow playback.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An information reproducing apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram centering on the magnetic tape running mechanism of the information reproducing apparatus of the first embodiment. The same parts as those of the conventional example will be briefly described with the same reference numerals. In FIG. 1, the magnetic tape 1 is
A control signal is recorded along one edge, an audio signal is recorded on the other edge, and a video signal (which may include an audio signal) is recorded on the inclined track at the center.

The magnetic tape 1 is a tape reel 2a on the supply side.
And the tape reel 2b on the winding side, and is guided to the drum 4 by the left and right guide posts 3a and 3b.
Magnetic heads 5a and 5b are attached to the drum 4, and the magnetic tape 1 is helically scanned. A part of the head switching signal generating circuit 6 is attached to the drum 4 as a head switching signal generating means, and the head switching signal of the magnetic head 5 is output at a specific rotation phase of the drum 4.

Unlike the conventional example, a control signal detecting head (hereinafter referred to as a control head) 20 and an audio recording / reproducing head (hereinafter referred to as an audio head) 21 are attached to the transfer path of the magnetic tape 1. A capstan 8, a pinch roller 9, a capstan motor 10, etc. are provided as tape transfer means between the audio head 21 and the tape reel 2b, which is a transfer path of the magnetic tape 1, as in the conventional example. . Also, the capstan motor 10
Has a capstan F as a means for generating a capstan pulse.
G10a is attached to generate a capstan pulse according to the rotation of the capstan 10. The control head 20 is a magnetic head using a magnetoresistive element (MR element), and is capable of detecting a control signal recorded on a control track of the magnetic tape 1 at a constant output level regardless of the transfer speed of the magnetic tape 1. You can The audio head 21 is a head for recording / reproducing audio signals.

On the other hand, a drum rotation drive circuit 11, a tape position calculation circuit 22, and a tape drive control circuit 23 are provided as circuit blocks for controlling the running mechanism of the magnetic tape 1. The drum rotation drive circuit 11 rotates the drum 4 at a constant speed, and synchronizes with the signal from the drum FG (not shown) attached to the drum 4 to synchronize the magnetic head 5 with the magnetic head 5.
Is rotated at a constant speed by the FG servo. The tape position calculation circuit 22 inputs the control signal of the control head 20, the capstan pulse of the capstan FG 10a, and the head switching signal of the head switching signal generation circuit 6, respectively, and the current recording track position of the magnetic tape 1 is determined by the magnetic head 5 It is a circuit that calculates based on the scanning start position on the track. When the tape position calculation circuit 22 receives a magnetic tape position (phase) signal from the tape position calculation circuit 22, the tape drive control circuit 23 outputs a rotational drive torque control signal to the capstan motor 10 to cause the magnetic head 5 to move to the recording track W. It is a circuit that matches the position (phase).

FIG. 2 is a signal arrangement diagram of the magnetic tape 1 used in the information reproducing apparatus of this embodiment. In the figure, a track W is a video track on which a video signal is recorded, and is a track which is helically scanned by the magnetic heads 5a and 5b at a normal speed. The track S1 is a control track on which a control signal is recorded along the lower edge of the magnetic tape 1. The magnetoresistive element is driven by a constant current by a current source (not shown), and the control head 20 scans the control track S1. Further, the track S2 is an audio track on which an audio signal is recorded along the upper edge of the magnetic tape 1. For the control signal, for example, a positive pulse is output in the odd field and a negative pulse is output in the even field via the control head 20. Further, the pitch of the control signal (pulse) recorded on the magnetic tape 1 corresponds to two pitches of the track W viewed from the tape transport direction,
It is assumed that the boundary is recorded so as to coincide with the boundary of the track W.

FIG. 3 is a diagram for explaining the operation of the information reproducing apparatus in the intermittent reproduction. FIG. 3A shows a capstan motor 10
Drive torque, (b) shows the head switching signal generated by the head switching signal generating circuit 6, (c) shows the control signal output from the control head 20, and (d) shows the output from the capstan FG 10a. The capstan pulse is shown. FIG. 4 is an explanatory diagram showing a signal processing procedure of the information reproducing apparatus of this embodiment.

The operation of the information reproducing apparatus of the first embodiment thus constructed will be described with reference to FIGS. In intermittent reproduction, the magnetic tape 1 must be intermittently fed in recording track units. Normally, the magnetic tape 1 is moved by an amount corresponding to one frame (2 tracks) of the video signal.

Α. The drum rotation drive circuit 11 rotates the drum 4 at a constant speed, and the head switching signal generation circuit 6 detects the head switching signal as shown in FIG. 3B. β. As shown in step P1 of FIG. 4, the tape position calculation circuit 2 receives the control signal, the capstan pulse, and the head switching signal obtained during the previous transfer of the magnetic tape 1.
Enter 2.

Γ. As shown in step P2 of FIG. 4, the tape position calculation circuit 22 detects the current position of the magnetic tape 1 by three input signals and calculates the target moving distance of the next magnetic tape 1 to the stop position. . This moving distance is set to a point offset by a distance L from the scanning start position of the track W1 during normal reproduction as in the case of the conventional example of FIG. 8 so that a sufficient reproduction output of the video signal can be secured from the magnetic head 5. Then, this point is set as the tape stop position.

Δ. In the next step P3, the magnetic tape 1
A torque curve of the capstan motor 10 is created based on the set moving distance of. If the intermittent movement is performed normally, the same torque curve is used every time. In this case, for example, the tension applied to the magnetic tape 1 changes smoothly.
A smooth torque curve as shown in FIG. Then, the tape drive control circuit 23 drives the capstan motor 10 from time t4 to transfer the magnetic tape 1.

Ε. As shown in FIG. 3 (d), the tape position calculation circuit 22 sets the first capstan pulse as P1 after the level of the head switching signal changes, counts the capstan pulse output subsequently to this, and counts the capstan pulse that is being transferred. Calculate the position of the magnetic tape 1. Then, the tape drive control circuit 23 outputs a torque control signal based on the tape position output from the tape position calculation circuit 22. Then, in step P4 of FIG. 4, the capstan 8 (capstan motor 1
Control is performed so that the driving torque of 0) changes smoothly.

Ζ. When the capstan pulse Pn corresponding to the stop position of the magnetic tape 1 is output, the tape drive control circuit 23 stops the rotation of the capstan motor 10 and ends the intermittent feeding of the magnetic tape 1.

As described above, in this embodiment, the magnetic tape 1 is transferred at a very low speed by replacing the conventional ring head as the control signal detecting head with the control head 20 composed of a magnetoresistive element. However, the running position of the magnetic tape 1 can be detected. Conventionally, tape transfer, which was conventionally controlled by time, torque, and rotation angle of the capstan shaft, can be controlled by only the control signal and the capstan pulse in this embodiment. Further, when the track width recorded on the magnetic tape 1 is deviated from the regular interval due to the expansion and contraction of the magnetic tape 1, if the capstan motor 10 is controlled by torque and time management, the magnetic tape 1 is conventionally stopped. Although it was difficult to bring the position to the target position, the magnetic tape 1 can be surely aligned by detecting the control signal with the control head 20 of the magnetoresistive element.

Further, the tape drive control circuit 23 can smooth the feeding of the magnetic tape 1 at the time of intermittent feeding by generating a torque control signal whose output value changes in a sine wave.
Tape feeding can be realized without burdening the magnetic tape itself. Moreover, a large amount of starting torque is not required, and the power consumption of the capstan motor 10 is reduced. This means that the performance of the capstan motor 10 is not required to be excessive, and as a result, the price of the capstan motor 10 can be reduced.

Next, an information reproducing apparatus according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram centering on the magnetic tape running mechanism of the information reproducing apparatus of the second embodiment. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. A drum rotation drive circuit 11, a tape phase calculation circuit 24, a tape drive control circuit 25, and a tape transfer speed calculation circuit 26 are provided as circuit blocks for controlling the running mechanism of the magnetic tape 1.

The drum rotation drive circuit 11 rotates the drum 4 at a constant speed, and rotates the magnetic head 5 at a constant speed by an FG servo in synchronization with a signal from the drum FG attached to the drum 4. The tape phase calculation circuit 24 includes a head switching signal from the head switching signal generation circuit 6, a control signal from the control head 20, and a capstan FG10.
This is a circuit for inputting each capstan pulse of a and calculating the phase of the current recording track of the magnetic tape 1 with reference to the scanning start position on the track of the magnetic head 5.
Further, the tape drive control circuit 25 is a tape phase calculation circuit 24.
When a magnetic tape phase signal is applied from the magnetic tape 1, a torque control signal for rotational drive is output to the capstan motor 10 to adjust the phase of the recording track of the magnetic tape 1 to a predetermined phase.

The tape transfer speed calculation circuit 26 is a capstan FG 10a attached to the capstan motor 10.
Is a circuit for detecting the rotation speed of the capstan 8 and calculating the transfer speed of the magnetic tape 1 from this. The signal of the transfer speed is given to the tape drive control circuit 25, and the speed of the magnetic tape 1 is controlled to the set transfer speed.

In the information reproducing apparatus of the second embodiment having such a configuration, only the case of special reproduction will be described. The special reproduction means that the magnetic tape 1 is transferred at a constant tape transfer speed different from that during recording, for example, slow reproduction or double speed reproduction such as double reproduction. First, the transfer speed of the magnetic tape 1 is controlled by the tape drive control circuit 25 so that the capstan pulse becomes constant per unit time.

In parallel with this control, the drum rotation drive circuit 1
1 rotates the drum 4 at a constant rotation speed so that the scanning speed of the magnetic head 5 becomes the same as that during normal reproduction. In this case, the angle at which the magnetic head 5 obliquely scans the magnetic tape 1 varies depending on the transport speed of the magnetic tape 1. At that time, as in the case of FIG. 8, it is necessary to determine the optimum value of the distance L (deviation amount) so that the magnetic head 5 scans as much of the track W1 recorded on the magnetic tape 1 as possible.

The distance L is individually set for each transfer speed of the magnetic tape 1, and the tape drive control circuit 25 controls the value to be a predetermined value. The distance L is detected by the tape phase calculation circuit 24 by processing the control signal, the head switching signal, and the capstan pulse as in the first embodiment.

As described above, in this embodiment, by changing the control head from the one using the ring head to the one using the magnetoresistive effect element, the magnetic tape 1 can be obtained.
Even if the transfer of the tape is very slow, the phase of the tape can be detected stably, and the intermittent reproduction and special reproduction functions can be surely realized.

In this embodiment, the rotational speed of the capstan 8 is detected by the capstan FG 10a, and the magnetic tape 1
Although the transfer speed of the magnetic tape 1 is detected, the transfer speed of the magnetic tape 1 can be detected by using the control signal, and the phase control and the transfer speed control of the magnetic tape 1 can be performed.

[0048]

As described above, according to the present invention, the head for detecting the control signal is changed from the conventional ring head to the control head composed of the magnetoresistive element, so that the transfer speed of the magnetic tape can be varied. Instead, the control signal can be detected stably. Therefore, the tape position can be adjusted with higher accuracy during intermittent feeding. The magnetic tape can be sent frame by frame to facilitate still playback. Therefore, it is not necessary to increase the transfer speed of the magnetic tape only for detecting the control signal as in the conventional case, and thus it is possible to realize an information reproducing apparatus which does not burden the magnetic tape.

Further, even in special reproduction such as slow reproduction, the signal from the control track can be detected stably, so that the magnetic tape transfer speed and the position of the magnetic tape can be surely detected, which is lower than the conventional one. Slow playback can be realized.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall configuration of an information reproducing apparatus in a first embodiment of the present invention.

FIG. 2 is a signal layout diagram of a magnetic tape used in the information reproducing apparatus of the present embodiment.

FIG. 3 is a signal waveform diagram showing the operating principle of the information reproducing apparatus in the first embodiment.

FIG. 4 is an explanatory diagram showing a signal processing procedure of the information reproducing apparatus in the first embodiment.

FIG. 5 is an explanatory diagram showing an overall configuration of an information reproducing apparatus in a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an example of the overall configuration of a conventional information reproducing apparatus.

FIG. 7 is a signal waveform diagram showing an operation principle of a conventional information reproducing apparatus.

FIG. 8 is an explanatory diagram showing a positional relationship between recording tracks of a magnetic tape and scanning tracks during still reproduction.

[Explanation of symbols]

 1 magnetic tape 2a, 2b tape reel 3a, 3b loading post 4 drum 5a, 5b magnetic head 6 head switching signal generation circuit 8 capstan 9 pinch roller 10 capstan motor 10a capstan FG 11 drum rotation drive circuit 20 control head 21 voice Head 22 Tape position calculation circuit 23, 25 Tape drive control circuit 24 Tape phase calculation circuit 26 Tape transfer speed calculation circuit

Claims (3)

[Claims] 1. A normal reproduction mode for reproducing a magnetic tape having a control track on which a control signal is recorded at a constant pitch and a video signal track on which a video signal is recorded, at the same transfer speed as during recording, and a magnetic tape. Has a still reproduction mode for stopping the transfer of the same video signal and reproducing the same video signal, a rotary head mounted on a rotary drum for recording and reproducing the signal on the video signal track, and a drum rotation for rotating the rotary drum at a constant speed. A drive unit, a head switching signal generation unit for generating a switching signal for the rotary head, and a tape including a capstan motor and a pinch roller for transferring the magnetic tape wound around a rotary drum between a supply reel and a take-up reel. The transfer means is attached to the rotation system of the capstan motor to rotate the capstan motor. In an information reproducing apparatus including a capstan pulse generating means for generating the same rotation pulse, a fixed control head composed of a magnetoresistive element for detecting a control signal of the magnetic tape, and a switching signal for the head switching signal generating means. The control signal of the control head and the rotation pulse of the capstan pulse generating means are respectively input to detect the distance difference between the track scanning start position of the rotation head and the recording start position of the recording track of the magnetic tape as a tape position. A tape position calculating means for calculating a tape target transfer amount at the time of minute feeding from the current tape position, and the magnetic tape is transferred at a set speed, and the tape position output from the tape position calculating means becomes a predetermined value. Control the magnetic tape at least Information reproducing apparatus characterized by comprising a tape drive control means for supplying to said tape transport means a drive control signal for transferring the raw mode. 2. The tape drive control means counts the number of rotation pulses output from the capstan pulse generation means from the current stop position of the magnetic tape to a predetermined position within a track interval of the recording tracks. The information reproducing apparatus according to claim 1, having a function of intermittent transfer. 3. A normal reproduction mode for reproducing a magnetic tape having a control track on which a control signal is recorded at a constant pitch and a video signal track on which a video signal is recorded, at the same transfer speed as during recording, and a magnetic tape. It has the functions of a still playback mode that stops the transport of the same video signal and plays back the same video signal, and a special playback mode that runs the magnetic tape at a transport speed different from that at the time of recording and plays back the video signal. A rotary head for recording / reproducing a signal on / from a signal track, a drum rotation driving means for rotating the rotary drum at a constant speed, a head switching signal generating means for generating a switching signal for the rotary head, and a rotary drum. Tape transfer including a capstan motor and a pinch roller for transferring the magnetic tape between a supply reel and a take-up reel And a capstan pulse generating means for generating a rotation pulse according to the rotation of the capstan motor, the magnetic tape being formed of a magnetic resistance element. A fixed control head for detecting the control signal, a switching signal of the head switching signal generation means, a control signal of the control head, and a rotation pulse of the capstan pulse generation means, respectively, and the track scanning start position of the rotation head. And a tape phase calculating means for detecting the distance difference between the recording start positions of the recording tracks of the magnetic tape as a tape phase, and a tape transfer speed detecting means for receiving the rotation pulse of the capstan pulse generating means and detecting the tape transfer speed. , The tape transfer speed detecting means Referring to the speed signal et output, with transferring the magnetic tape at a set speed,
A tape drive that controls the tape phase output from the tape phase calculation means to a predetermined value and supplies a drive control signal for transferring the magnetic tape in a special reproduction mode including at least slow reproduction to the tape transfer means. An information reproducing apparatus comprising: a control unit.