JPH05292449A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide short-time reproducing which can reproduce pictures without missing the reproducing envelop of pictures and can recognize both of pictures and sounds. CONSTITUTION:At the time of SP head reproducing in the case of SP mode reproducing at (N+1)/N-times speed, at a part to trace a recording pattern part at a different azimuth angle, a first head switching signal synchronized to a head switching pulse is prepared by a head switching signal generating means 3B and corresponding to this head switching signal, the SP head is switched to an adjacent EP head so as to pick up the reproducing envelop. At the time of EP head reproducing in the case of EP mode reproducing at (N+1)/N-times speed, at a part to trace the recording pattern part at the different azimuth angle, a second head switching signal synchronized to the head switching pulse is prepared by a head switching signal generating means 3C and corresponding to this head switching signal, the EP head is switched to the adjacent SP head so as to pickup the reproducing envelop.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a (N + 1) /
The present invention relates to a magnetic recording / reproducing device for reproducing at N times speed.

[0002]

2. Description of the Related Art Conventionally, a video tape recorder (VTR)
In the magnetic recording / reproducing apparatus such as the above, various special reproduction speed systems have been considered and implemented. In addition to normal playback (1x speed playback at the same speed as recording), double speed playback (2x speed playback) and speed search (3x, 5x, 7x, 9x, 15x, 21x) as special playback , 2
7x speed) and slow playback (1/4, 1/10, 1/15, 1 / 30x speed)
Is being implemented. In these reproductions, by controlling the speed of the capstan motor that conveys the tape and slightly correcting the speed of the cylinder motor, the frequency f of the horizontal synchronizing signal obtained from the correlation with the tape speed is obtained.
It is necessary to keep H at a nearly regular frequency. With the head built into the cylinder, at special playback speeds other than normal playback, the trace angle differs from the format recording pattern.
A noise bar appears. Therefore, in double speed playback and slow speed playback, the heads with different azimuth angles are paired and the double azimuth 4 heads mounted facing 180 ° are selected and used to determine the trace position so that noise does not appear on the screen. However, noiseless playback is performed.

By the way, when the recorded tape is reproduced, the normal reproduction takes the same time as the recorded time. In double speed reproduction, the reproduction time is halved, but the sound is too fast to understand even if it is audible. If the speed is less than double speed, it becomes possible to recognize the voice,
As for the video, the reproduction trace gradually shifts from the recording track pattern and enters different azimuth angle portions, which causes a problem that the reproduction envelope is missing.

[0004]

As described above, in the conventional magnetic recording / reproducing apparatus, the reproduction time of the normal reproduction is the same as the recorded time. In double speed playback, the playback time is halved, but the voice is too fast to understand.

In view of the above problems, it is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of realizing time-reduced reproduction capable of recognizing both video and audio and producing leisure time.

[0006]

The invention according to claim 1 is
Double azimuth 4 with a pair of standard mode heads (referred to as SP heads) and long time mode heads (referred to as EP heads) with different azimuth angles, mounted 180 ° opposite to each other
Using the head rotation cylinder, controlling the capstan motor for both SP mode and EP mode,
A magnetic recording / reproducing apparatus for conveying and reproducing a tape at a speed of (N + 1) / N (N is an integer of 3 or more) times the normal reproduction speed, and means for designating (N + 1) / N double speed reproduction, By specifying (N + 1) / N double speed reproduction, speed target value shifting means for shifting the target value for (N + 1) / N double speed with respect to the normal reproduction speed target value, and a control signal (N + 1) issued from the running tape. Control frequency conversion means for converting to N signals, target value of the speed target value shift means, speed detection means for speed detecting a speed detection signal detected from a capstan motor, and phase detection signal detected from the rotary cylinder. A head switching pulse generating means for generating a head switching pulse, and a control signal from the control frequency converting means. Based on the phase detection means for phase-detecting the head switching pulse, and the speed detection signal from the speed detection means and the phase detection signal from the phase detection means, the rotational speed of the capstan motor at (N + 1) / N times speed. And a capstan motor control signal generating means for generating a capstan motor control signal for controlling the phase, and (N + 1) / N speed SP mode reproduction,
A first head switch that generates a head switch signal for switching to an EP head adjacent to the SP head at a portion tracing a recording pattern portion having a different azimuth angle during reproduction by the SP head. Signal generation means and EP of (N + 1) / N times speed
In the mode reproduction, a head switching signal for switching to an SP head adjacent to the EP head is generated in synchronization with the head switching pulse in a portion tracing a recording pattern portion having a different azimuth angle during reproduction by the EP head. 2 head switching signal generating means.

Further, in the invention of claim 2, in the structure of claim 1, in (N + 1) / N times speed EP mode reproduction, the capstan motor is performing (N + 1) / N times speed constant speed rotation reproduction, In a portion where the tracking margin of the reproduction trace is reduced, a means for generating a capstan acceleration pulse synchronized with the head switching pulse and applying it to the capstan motor control signal is provided.

[0008]

[Operation] In the present invention, when the tape is conveyed at (N + 1) / N times speed, the reproduction trace angle differs with respect to the tape recording pattern. Therefore, during SP mode reproduction, the SP head is temporarily switched to the EP head, E during mode playback
The P head is temporarily switched to the SP head to pick up the reproduction envelope. Furthermore, in the case of EP mode reproduction, (N + 1)
During the / N speed constant rotation, the acceleration pulse is applied to the capstan motor in synchronization with the video head switching pulse for the portion where the tracking margin is reduced, and more reproduction envelopes are picked up. By switching the SP and EP heads as described above, by applying the capstan acceleration pulse in the EP mode, the reproduction envelope can be detected without omission even at the (N + 1) / N speed. As a result, it is possible to realize shortened playback in which both video and audio can be recognized. For the cylinder control, horizontal synchronization frequency (fH) correction according to (N + 1) / N speed is applied, and roll correction is added to the cylinder to suppress fH fluctuation even when a capstan acceleration pulse is applied. A pseudo vertical synchronizing signal is inserted in the reproduced video signal obtained by (N + 1) / N times speed reproduction to prevent vertical vibration on the monitor.

[0009]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is an overall block diagram of a magnetic recording / reproducing apparatus according to the present invention.

The embodiment shows a block diagram of a magnetic recording / reproducing apparatus at the time of reproducing, and a standard mode (hereinafter referred to as S
The designation of the P mode) or the long time mode (hereinafter referred to as the EP mode) is performed on the servo microcomputer 3 by means not shown.

In FIG. 1, reference numeral 1 is a key input section for designating (N + 1) / N times speed (for example, 4/3 times speed) reproduction, and 2 corresponds to (N + 1) / N times speed designation from the key input section 1. It is a system control microcomputer that outputs the specified speed. A servo microcomputer 3 controls the cylinder motor unit 4 and the capstan motor unit 5. Servo microcomputer 3
Is the speed designation data from the system control microcomputer 2, the speed detection (FG) signal of the capstan motor unit 5 that conveys the tape, and the reproduction control (CTL) signal (phase detection signal) from the control head unit 6. Based on this, the capstan motor unit 5 is controlled in speed and phase. Further, the servo microcomputer 3 is based on the reference signal (vertical synchronization signal or signal from the reference oscillator), the speed detection (FG) signal of the cylinder motor unit 4, and the phase detection (PG) signal of the motor unit 4. , Control the speed and phase of the cylinder motor unit 4. Here, in the speed control of the cylinder motor unit 4, since the horizontal synchronizing frequency (fH) of the reproduction signal is deviated in (N + 1) / N speed reproduction, the motor rotation speed of the cylinder motor unit 4 is corrected according to the tape speed ( f
H correction). In addition, the servo microcomputer 3
Head switching pulse (SW pulse) for performing head switching for each half rotation of the cylinder based on the phase detection (PG) signal detected from the cylinder motor unit 4.
In order to prevent the reproduction envelope from being lost at the portion for tracing the recording pattern having different azimuth angles during reproduction by the SP head in the SP mode reproduction of (N + 1) / N times speed. An EP head adjacent to the SP head in synchronization with the switching pulse (the other of the pair of double azimuth heads)
Means 3B for producing a head switching signal for switching to
And (N + 1) / N times speed EP mode reproduction, E
During reproduction by the P head, in order to prevent the reproduction envelope from being lost at the portion where the recording patterns having different azimuth angles are traced, in synchronization with the switching pulse, the SP head adjacent to the EP head (pair (N + 1) / means 3C for creating a head switching signal for switching to the other of the eggplant double azimuth heads)
In order to prevent vertical synchronization failure (longitudinal vibration) of the monitor due to noise in N-speed reproduction, a means 3D for generating a pseudo vertical synchronization signal based on the phase detection (PG) signal from the cylinder motor unit 4 is provided. ..

FIG. 2 is a block diagram of the capstan control portion in FIG. In FIG. 2, the servo microcomputer 3
The following means 31 to 3 serve as capstan control means.
Have 7. That is, the servo microcomputer 3 inputs the speed designation data from the system control microcomputer 2 and sets a target value shift means 31 for setting a target value according to the designated speed, and a speed detection signal (from the FG input terminal T2). F
G pulse) and the target speed signal from the target value shift means 31 to create a DC voltage proportional to the frequency of both signals, and a speed detection means (AFC detection means) 32 that takes the difference between the two voltages, Frequency conversion means 33 for frequency-converting the control signal (CTL signal) from the running tape (that is, CTL input terminal T1) using the FG pulse, and phase detection means for phase-comparing the frequency-converted CTL signal with the head switching pulse. (APC detection means) 34, a mix filter 35 that mixes and outputs a speed detection output and a phase detection output, and a reproduction trace tracking while the capstan motor is rotating at a specified speed of (N + 1) / N times speed in EP mode reproduction. In order to accelerate the capstan motor at the part where the margin becomes small, head switching pulse (SW
Pulse) and an acceleration pulse processing means 36 for generating a capstan acceleration pulse on the output of the mix filter 35, and an output of the mix filter 35 passing through the acceleration pulse processing means 36 according to an output value. And a PWM output processing means 37 for performing pulse width modulation (PWM) and outputting.

Further, the capstan motor section 5 receives a capstan motor control signal from the output terminal T3 of the servo microcomputer 3 at one input terminal thereof as a low pass filter (LPF) 5.
A differential amplifier 53 that receives a differential output from the reference value circuit 52 by inputting the reference voltage from the reference value circuit 52 to the other input terminal.
A drive circuit 54 for amplifying the difference output, a capstan motor 55 driven by the drive output, FG detection means 56 for detecting an FG pulse from the motor 55,
An amplifier 57 and a Schmitt circuit 58 for amplifying and shaping the detected FG pulse are provided.

The control head unit 6 comprises a control head 61 for detecting a CTL signal from the running tape, an amplifier 62 for amplifying and shaping the detected CTL signal, and a Schmitt circuit 63.

The speed control of the capstan will be described with reference to FIG. Here, N at (N + 1) / N times speed
The case of = 3 will be described. Speed detection is the same as before.
It is performed by a capstan FG pulse. The FG pulse is amplified and shaped, and is input to the servo microcomputer 3 as a speed detection signal. When 4/3 times speed playback is specified, the target value is shifted by 4/3 times speed (1.33 times speed) from the speed target value for normal playback. For example, if the FG detection signal is normal reproduction (1 × speed) 1080 Hz, then 1080 Hz × 4/3 = 1440 Hz is set as the speed control target value at 4/3 times speed. The speed detection is performed by detecting the FG pulse and the speed target signal of 4/3 times speed.

The phase detection is C detected from the running tape.
By amplifying and shaping the TL signal and inputting it to the servo microcomputer 3, 4 CTL signals are frequency-converted into 3 using FG pulse and phase detection is performed with the head switching pulse. Double speed phase detection is performed. The results of the velocity detection and the phase detection are passed through the mix filter 35 in the microcomputer, subjected to the acceleration pulse processing, and then subjected to the PWM output processing, and output from the servo microcomputer 3 as a capstan motor control signal. Then, the capstan motor control signal is smoothed by the low-pass filter 51, sent to the motor drive IC 54, compared with the reference voltage, and the motor 55 is compared.
Drive. The tape speed is 4 /
It is controlled at 3x speed (1.33x speed).

FIG. 3 shows the cylinder head arrangement of the double azimuth four head. On the rotary cylinder 7, standard mode heads SP1 and SP2 are arranged 180 ° opposite to each other, and similarly, long mode heads EP1 and EP2 are arranged 180 ° opposite to each other. SP1 and EP1 have the same azimuth angle, and SP2 and EP2 have the same azimuth angle. The standard mode heads (SP1, SP2) and the long time mode heads (EP1, EP2) have different azimuth angles, so SP1 and EP2 are different azimuth angles, and SP2 and EP1 are also different. The azimuth angle. The above heads constitute a double azimuth 4 head. Further, the high-fidelity voice heads SA and SB are arranged on the rotary cylinder 7 so as to face each other by 180 °.

FIG. 4 shows the heads SP1, SP2, EP1, EP2, SA, SB in the cylinder head arrangement of FIG.
2 shows the head mounting height and the head width.

Next, the reproduction envelope by the video head attached to the rotary cylinder will be described.

FIG. 5 shows an SP mode self-recording tape 4/3 double speed track pattern diagram. The horizontal axis represents time, and the vertical axis represents the tape longitudinal direction, showing the track width and the head width. At 4/3 times speed, the reproduction trace position gradually shifts from the recording pattern due to the speed of advancing recording control by 4 shots with respect to 3 cycles of the head switching pulse (SW pulse), and is repeated in 3 cycles of the SW pulse. .. Outputs signals of 6 fields out of 8 fields of recording track,
It will be shortened playback that cuts the field. Since the reproduction trace position deviates from the recording pattern, the three phases, which are often applied to the recording pattern portions having different azimuth angles, are switched to the EP head. In other words, in SP mode, the head used is (1) SP1 → (2) SP2 → (3) EP2 → (4) EP
1 → (5) EP2 → (6) SP2 is repeated. (2) SP2 to (3) EP2 part and (5) EP2 of the above-mentioned use head
From (6) In the SP2 part, each one field is cut, and playback is shortened. The shaded portion in FIG. 5 is the envelope portion obtained by SP mode 4/3 speed reproduction, which is noiseless reproduction. For the cylinder control, the horizontal sync frequency (fH) is corrected according to the 4/3 speed. A pseudo vertical sync signal is inserted in the reproduced video signal to prevent vertical vibration on the monitor.

FIG. 6 shows a SP mode 4/3 times speed timing chart.

In FIG. 6, (a) shows a head switching pulse (SW pulse) created from the phase detection signal (PG signal) of the cylinder motor part, and (b) is created in synchronization with the head switching pulse. SP head and EP
The head switching signal for switching the head is shown. While the head switching signal is at high level, SP
The head switching state of SP1 and SP2 of the head is switched to EP2 and EP1 of adjacent EP heads forming a double azimuth head. (c) shows the head used during 4/3 speed reproduction. (d) is a control signal (CTL signal) detected by the control head section 6 from the running tape, and (e) is a phase control obtained by frequency conversion of the CTL signal of (d) during 4/3 speed reproduction. CT for
The L signal is shown. (f) shows the playback envelope waveform at 4 / 3x speed, and (g) shows an example of the pseudo vertical sync signal (phase shift example) that is impressed on the video signal obtained at 4 / 3x speed playback. ing. By inserting this pseudo vertical synchronizing signal, vertical vibration on the image monitor is prevented.

FIG. 7 shows an EP mode 4/3 double speed track pattern diagram. Since the reproduction trace position deviates from the recording pattern, one phase which is often applied to the recording pattern portions having different azimuth angles is switched to the SP head. That is,
The head used is (1) EP1 → (2) EP2 → (3) EP1 →
(4) EP2 → (5) EP1 → (6) SP1 is repeated. From (5) EP1 to (6) SP1 part of the head used above
(6) From SP1 to (1) EP1 part, each one field is cut and shortened time reproduction is performed. The shaded portion A in FIG. 7 is the envelope portion obtained by 4/3 speed reproduction in EP mode, which is noiseless reproduction.

As is clear from FIG. 7, since the reproduction trace position deviates from the recording pattern, the head used
(1) Since the tracking margin is reduced at the beginning of EP1 and (5) at the end of EP1, the linearity of the playback track is partially undulated by applying the capstan acceleration pulse, and the diagonal line in the figure As shown by, the envelope amount is increased, the tracking margin is increased, and noiseless reproduction is performed. In the EP mode, since the reproducing head width is wider than the recording track width, it is possible to output hi-fi sound during 4/3 speed reproduction.

For the cylinder control, horizontal sync frequency (fH) correction corresponding to 4/3 times speed is applied. At the time of applying the capstan acceleration pulse, a roll correction pulse is applied to the cylinder in order to suppress fH fluctuation. Since the head of the reproduced video signal is switched and a shift of αH occurs, a pseudo vertical sync signal is inserted to prevent vertical vibration on the monitor.

FIG. 8 shows an EP mode 4/3 speed chart.

In FIG. 8, (a) shows a head switching pulse (SW pulse) created in synchronization with the PG signal of the cylinder motor section, and (b) shows an EP head and an SP head created from the head switching pulse. And the head switching signal. This head switching signal is set to a high level in the EP mode, and EP1 and EP of the EP head are changed.
It is placed in the head switching state of 2, but during the low level period, it is switched to the SP1 head adjacent to the EP2 head. (c) shows the head used during 4/3 speed reproduction. (d) is a control signal (CTL signal) detected by the control head section 6 from the running tape, and (e) is a phase control obtained by frequency conversion of the CTL signal of (d) during 4/3 speed reproduction. Shows a CTL signal for the. (f)
Shows the playback envelope waveform at 4/3 times speed,
(g) shows a capstan acceleration pulse created in synchronization with the head switching pulse. (h) shows a cylinder roll correction pulse supplied to the cylinder motor unit in order to suppress fluctuations in the horizontal synchronizing frequency (fH) when a capstan acceleration pulse is applied. (i) shows an example of a pseudo vertical synchronization signal (phase shift example) that is impressed on a video signal obtained at 4/3 speed reproduction. By inserting this pseudo vertical synchronizing signal, vertical vibration on the image monitor is prevented. In FIG. 8 (f), the shaded area A indicates the tracking margin increase that is corrected by the capstan acceleration pulse in the reproduction envelope waveform.

According to the above embodiment, the SP and E of the VTR are
When performing 4/3 times speed playback (playback in which the recording pattern and the playback pattern are slightly deviated) on the recorded tape in P mode, switch the video head or apply a capstan acceleration pulse according to each mode. By doing so, you can make up for the missing playback envelope,
Noiseless playback is possible.

This shortened playback speed (4/3 times speed) is a level at which both video and audio can be recognized, and is, for example, 60.
The minute recording tape can be played in 45 minutes, producing 15 minutes of leisure time.

In the above embodiment, the case of (N + 1) / N double speed reproduction was explained for N = 3, but if N is an integer of 3 or more, the same operational effect can be obtained.

[0031]

As described above, according to the present invention, (N
+1) / N times speed reproduction (greater than 1 times speed), S
In P mode, the head is temporarily switched to the EP head during playback.
In the P mode, by temporarily switching to the SP head, even if the head trace enters a different azimuth angle portion due to a slight deviation between the recording pattern and the reproducing pattern in each mode during tape running, the reproducing envelope is not lost. It can be played without noise. Therefore, it is possible to realize a time-reduced reproduction in which both video and audio can be recognized, and it is possible to generate leisure time and the like.

[0032]

[Brief description of the drawings]

[0033]

FIG. 1 is an overall block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

[0034]

FIG. 2 is a block diagram of a capstan control part in FIG.

[0035]

FIG. 3 is a layout view of heads mounted on a rotating cylinder.

[0036]

FIG. 4 is a diagram showing a height and a head width of a cylinder head in FIG.

[0037]

[Figure 5] SP mode self-recording tape 4/3 double speed track pattern diagram.

[0038]

FIG. 6 SP mode 4/3 double speed timing chart.

[0039]

[FIG. 7] EP mode 4/3 double speed track pattern diagram.

[0040]

[FIG. 8] EP mode 4/3 double speed timing chart.

[0041]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Key input part 4 ... Cylinder motor part 5 ... Capstan motor part 6 ... Control head part 31 ... Target value shift means 32 ... Velocity detection means 33 ... Frequency conversion means 34 ... Phase detection means 35 ... Mix filter 36 ... Acceleration pulse Processing means 37 ... PWM output processing means 35, 37 ... Capstan motor control signal generating means 55 ... Capstan motor 56 ... Speed detecting means 61 ... Control head

Claims (2)

[Claims] 1. A pair of SP and EP heads having different azimuth angles and a double azimuth 4-head rotary cylinder mounted opposite to each other are used to control a capstan motor in each of SP mode and EP mode. , (N + 1) / N for normal playback speed (N is an integer of 3 or more)
A magnetic recording / reproducing apparatus which conveys and reproduces a tape at a double speed, wherein a means for designating (N + 1) / N double speed reproduction and a designation of (N + 1) / N double speed reproduction with respect to a speed target value for normal reproduction. (N + 1) / N speed target value shifting means for shifting the target value, and a control signal (N + 1) detected from the running tape.
Control frequency converting means for converting the output to N output, a speed detecting means for speed detecting a target value of the speed target value shifting means, and a speed detection signal detected by a capstan motor, and a phase detected by the rotary cylinder. Head switching pulse generation means for generating a head switching pulse based on the detection signal, phase detection means for phase detecting the control signal and the head switching pulse from the control frequency conversion means, and speed detection from the speed detection means Capstan motor control signal generation for generating a capstan motor control signal for controlling the rotation speed and phase of the capstan motor at (N + 1) / N times speed, based on the signal and the phase detection signal from the phase detection means. Means and (N + 1) / N speed SP mode playback , A head for generating a head switching signal for switching to an EP head adjacent to the SP head in synchronization with the head switching pulse at a portion tracing a recording pattern portion having a different azimuth angle during reproduction by the SP head. The switching signal generating means and the (N + 1) / N double speed EP mode reproduction, adjacent to the EP head in synchronization with the head switching pulse, in a portion tracing a recording pattern portion having a different azimuth angle during reproduction by the EP head. And a second head switching signal generating means for generating a head switching signal for switching to the SP head. 2. A pair of SP and EP heads having different azimuth angles and a double azimuth four-head rotary cylinder mounted opposite each other by 180 ° are used to control the capstan motor in each of the SP mode and the EP mode. , (N + 1) / N for normal playback speed (N is an integer of 3 or more)
A magnetic recording / reproducing apparatus which conveys and reproduces a tape at a double speed, wherein a means for designating (N + 1) / N double speed reproduction and a (N + 1) / N double speed reproduction for a speed target value for normal reproduction ( N + 1) / N speed target value shifting means for shifting the target value, and a control signal (N + 1) detected from the running tape.
Control frequency converting means for converting the output to N output, a speed detecting means for speed detecting a target value of the speed target value shifting means, and a speed detection signal detected by a capstan motor, and a phase detected by the rotary cylinder. Head switching pulse generation means for generating a head switching pulse based on the detection signal, phase detection means for phase detecting the control signal and the head switching pulse from the control frequency conversion means, and speed detection from the speed detection means Capstan motor control signal generation for generating a capstan motor control signal for controlling the rotation speed and phase of the capstan motor at (N + 1) / N times speed, based on the signal and the phase detection signal from the phase detection means. Means and (N + 1) / N speed SP mode playback , A head for generating a head switching signal for switching to an EP head adjacent to the SP head in synchronization with the head switching pulse at a portion tracing a recording pattern portion having a different azimuth angle during reproduction by the SP head. The switching signal generating means and the (N + 1) / N double speed EP mode reproduction are adjacent to the EP head in synchronization with the head switching pulse in a portion tracing a recording pattern portion having a different azimuth angle during reproduction by the EP head. The second head switching signal generating means for generating a head switching signal for switching to the SP head and the EP mode reproduction of (N + 1) / N times speed, the capstan motor is performing the constant speed rotation reproduction of (N + 1) / N times speed. In addition, in the part where the tracking margin of the playback trace is reduced, the head switch It generates a capstan acceleration pulse synchronized with quenching pulse, the magnetic recording and reproducing apparatus characterized by comprising a means for applying to said capstan motor control signal.