JPH10262204A - Rotary head recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary head recording and reproducing device in which synchronization of a drum is easily executed even when an analog signal and a digital signal is switched for recording and reproducing. SOLUTION: This device is composed of an analog signal recording and reproducing circuit 109 that conducts recording and reproducing processing of an analog signal and generates an analog reference signal, a digital signal recording and reproducing circuit 111 that conducts recording and reproducing processing of a digital signal and generates a digital reference signal, a drum 100 on which on which an analog signal recording and reproducing head and a digital signal recording and reproducing head to record or reproduce a recording signal to/from a magnetic recording medium are mounted and a drum control circuit 104 that controls the revolution of the drum based on the analog reference signal and the digital reference signal. In this case, the digital reference signal is generated so as to be in the same phase with the analog reference signal and further, after the digital reference signal is synchronized with the rotating phase of the drum 100, the reference signal for drum control and signal processing are switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head recording / reproducing apparatus for recording / reproducing signals on a magnetic tape using a magnetic head mounted on a rotating drum, and more particularly to recording / reproducing both analog video signals and digital signals. It concerns a possible device.

[0002]

2. Description of the Related Art A digital signal recording apparatus for recording a digital video signal on a magnetic tape by using a rotary head has been developed.
It is described in JP-A-5-174496.

[0003]

However, the above technique does not take into account the dual use of recording and reproduction of analog video signals. In a device that combines the recording and reproduction of an analog video signal and the recording and reproduction of a digital signal, for example, when recording and reproducing an analog video signal, a vertical synchronization signal in an input video signal during recording, and an analog recording and reproduction circuit during reproduction. The reference clock obtained by dividing the reference clock is synchronized with the rotation of the drum, and the analog video signal recording / reproducing head mounted on the drum records and reproduces the analog video signal. On the other hand, when recording and reproducing a digital signal, the rotation of the drum is synchronized with a reference signal obtained by dividing the reference clock of the digital recording and reproducing circuit during recording and reproduction, and the analog video signal recording and reproducing head on the drum is used. The digital signal recording / reproducing is performed by a digital signal recording / reproducing head attached to a position different from the above. In this case, when the signal to be recorded / reproduced is switched between analog and digital, the reference signal for controlling the rotation of the drum is switched, so it is necessary to resynchronize the reference signal and the rotation of the drum in accordance with the signal processing. There's a problem.

An object of the present invention is to provide a rotary head recording / reproducing apparatus which can easily synchronize drums even when recording / reproducing of an analog video signal and a digital signal are switched.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an analog signal recording / reproducing circuit for recording / reproducing an analog signal and generating a reference signal for drum rotation control at the time of recording / reproducing an analog signal. A digital signal recording / reproducing circuit for generating a reference signal for drum rotation control at the time of digital signal recording / reproducing, and recording / reproducing of a recording signal generated by the analog / digital recording / reproducing circuit on a magnetic recording medium. A drum on which an analog signal recording / reproducing head and a digital signal recording / reproducing head are mounted; and a drum control circuit for controlling rotation of the drum based on reference signals generated by the analog and digital signal recording / reproducing circuits. In the rotary head recording / reproducing device, the digital signal is generated by the digital signal recording / reproducing circuit. The phase of the drum rotation control reference signal is given a predetermined phase difference with respect to the signal processing timing of the digital signal recording / reproducing circuit, and the phase of the drum rotation control reference signal generated by the analog signal recording / reproducing circuit. Synchronizing means for synchronizing the timing of the drum rotation control reference signal generated by the digital signal recording and reproducing circuit with the rotational phase of the drum is provided, and the digital signal recording and reproducing is performed by the synchronizing means. After the reference signal for drum rotation control generated by the circuit is processed so as to be synchronized with the rotation of the drum, that is, the timing of the recording / reproduction processing of the digital signal recording / reproduction circuit is synchronized with the rotation phase of the drum with a predetermined phase difference. By switching the reference signal for drum control and the signal processing.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration example of a rotary head recording / reproducing apparatus according to the present invention. In the figure, 100 is a drum, 101
Reference numerals a and 101b denote magnetic heads that record and reproduce analog video signals, and 102a and 102b denote magnetic heads that record and reproduce analog audio signals or digital signals.
3 is a detector for detecting the rotational position of the drum, 104 is a drum control circuit for controlling the rotation of the drum, and 105 is the drum 1
A head switching circuit for switching between the two magnetic heads 101a and 101b on the drum 100; a head switching circuit for switching between the two magnetic heads 102a and 102b on the drum 100; 108, a switching circuit for switching the reference signal of the drum control circuit, 109, an analog signal recording / reproducing circuit for recording / reproducing analog signals, and 110, an oscillation circuit for generating a reference clock for recording / reproducing analog signals. 111, a digital signal recording / reproducing circuit for recording / reproducing digital signals; 112, a timing generating circuit for generating timing for recording / reproducing digital signals; 113, an oscillation circuit for generating a reference clock for recording / reproducing digital signals , 114 perform control of a recording / reproducing mode, etc. The control circuit such as a microprocessor, 115, and 116 are input of the analog signal, an output terminal, the input and output terminals of the digital signal 117, 118 is a capstan, 119 is a magnetic tape. In FIG. 1, both the analog signal and the digital signal are used for both recording and reproduction. However, the same applies to a configuration in which each is independent.

As shown in FIG. 2, the magnetic heads 101a and 101b and 102a and
2b is attached at an angle α on the drum 100, and the drum 100 rotates in the direction of the arrow in the figure.

First, recording and reproduction of an analog video signal will be described. When recording / reproducing an analog signal, the switching circuits 107 and 108
Side.

At the time of recording, an analog signal is inputted from an input terminal 115 to an analog signal recording / reproducing circuit 109.
The analog video signal processed by the analog signal recording / reproducing circuit 109 is supplied to the drum 100 via the head switching circuit 105.
From the upper magnetic heads 101a and 101b, an analog audio signal is supplied to a switching circuit 107 and a head switching circuit 106.
Through the magnetic heads 102a and 102 on the drum 100
b is recorded on the magnetic tape 119. Also, at this time,
The analog signal recording / reproducing circuit 109 extracts a synchronizing signal from the input analog video signal, and uses the extracted signal as a drum control reference signal via the switching circuit 108 via the switching circuit 108.
04.

FIG. 3 is an operation timing chart of the drum control circuit 104 when recording an analog signal. Drum control circuit 1
In step 04, the rotation of the drum 100 is controlled so that the analog reference signal from the switching circuit 108 and the head position signal detected by the detector 103 have a predetermined phase β, which will be described in detail later. At the same time, a head switching signal is generated.
For example, the video head switching signal selects the head 101a when it is at the L level and selects the head 101b when it is at the H level. Similarly, when the audio head switching signal is at the L level, for example, the head 102a is selected,
At the time of the H level, the head 102b is selected.
However, the magnetic heads 102a, 1
Numeral 02b denotes magnetic heads 101a, 1 for recording and reproducing video signals.
01b, the magnetic heads 101a, 1b for recording and reproducing video signals.
In order to record and reproduce signals on the magnetic tape 119 with a phase difference α with respect to the video head switching signal, the audio head switching signal needs to have a phase difference α with respect to the video head switching signal. With these head switching signals, the head switching circuit 1
The video signal and the audio signal are sequentially recorded on the magnetic tape 119 by controlling the image signals 05 and 106. FIG. 4 shows an example of a pattern of a video signal recorded on the magnetic tape 119.

In the control by the drum control circuit 104 during reproduction, the reference signal only changes from a synchronizing signal in the input analog video signal to a signal generated based on the clock of the oscillation circuit 110, and the timing of FIG. Same as time. That is, the analog video signals sequentially reproduced by the heads 101a and 101b and the phase difference α
The audio signals sequentially reproduced by a and b are converted to a head switching circuit 105 and a head switching circuit 106, respectively.
The signal is input to the analog recording / reproducing circuit 109 via the switching circuit 107, subjected to signal processing, and output from the output terminal 116.

It is to be noted that the drum 1 for recording and reproducing analog signals
The rotation number of 00 is usually synchronized with the frame period of the analog video signal. For example, 30 / 1.001 Hz.

Next, recording and reproduction of a digital signal will be described. At the time of recording / reproducing a digital signal, the switching circuits 107 and 108 are connected to the digital signal recording / reproducing circuit 11.
1 and switching to the timing generation circuit 112 side.

At the time of recording, a digital signal is input to the digital signal recording / reproducing circuit 111 from the input / output terminal 117. The digital signal processed by the digital signal recording / reproducing circuit 111 is transferred to the magnetic head 102 a on the drum 100 via the switching circuit 107 and the head switching circuit 106.
Recorded on the magnetic tape 119 from 102b. At the time of reproduction, signals sequentially reproduced from the magnetic heads 102a and 102b are input to a digital signal recording / reproduction circuit 111 via a head switching circuit 106 and a switching circuit 107.
After being subjected to signal processing, it is output from the input / output terminal 117.

Here, an example of a digital signal to be recorded and reproduced by using the present apparatus will be described with reference to the drawings.

FIG. 5 shows an example of a recording pattern of one track. 3 is a subcode recording area for recording subcodes such as time information and program information, 7 is a data recording area for recording a digital compressed video signal, 2 and 6 are preambles of the respective recording areas, and 4 and 8 are respective recording areas. Area postamble, 5 is the gap between recording areas, 1
And 9 are margins at the track end. Of course, digital signals other than digital compressed video signals and audio signals may be recorded in the recording areas 3 and 7. Further, a digital compressed audio signal may be recorded in the area 7 together with the digital compressed video signal.

FIG. 6 is an example of a block configuration of each area. FIG. 6A is a block configuration example of the data recording area 7. 20 is a synchronization signal, 21 is ID information, 22 is data,
23 is a parity (C1 parity) for the first error detection and correction. For example, the synchronization signal 20 is 2 bytes, ID
The information 21 is composed of 3 bytes, the data 22 is composed of 99 bytes, and the parity 23 is composed of 8 bytes.
It is composed of 2 bytes. FIG. 6B is an example of a block configuration of the subcode recording area 3. In the block of the subcode recording area, the synchronization signal 20 and the ID information 21 are the same as those in FIG. 6A, the data 22 is composed of 19 bytes, and the parity 23 is composed of 4 bytes.
It is composed of 28 bytes, which is 1/4 of the block of (a).

FIG. 7 shows a configuration example of the ID information 21. 3
1 is a sequence number, 32 is a track address, 33 is a block address in one track, 35 is a sequence number 31, a track address 32 and a block address 3
3 is a parity for detecting error 3. this house,
The block address 33 is an address for identifying a block in each recording area. For example, 0 to 335 in the data recording area 7 and 0 to 1 in the subcode recording area 3
5 is assumed. The track address 32 is an address for identifying a track. For example, the address is changed in units of one track or two tracks, and 0 to 5 or 0
By setting to 2, six tracks can be identified. The sequence number 31 is changed in units of six tracks identified by the track address 32, for example,
Thus, 72 tracks can be identified. By synchronizing the track address with a cycle of a second error correction code described later, processing at the time of recording and identification at the time of reproduction can be facilitated.

FIG. 8 shows the data structure of one track in the data recording area 7. Note that the synchronization signal 20 and the ID information 21 are omitted. The data recording area 7 is composed of, for example, 336 blocks.
The data 41 and the header 44 are recorded in the block, and the second error correction code (C2 parity) 43 is recorded in the next 30 blocks. For example, the C2 parity 43 divides data of 306 blocks × 6 tracks into 18 in units of 6 tracks, and adds 10 blocks of C2 parity to each 102 blocks. For example, a Reed-Solomon code may be used as the error correction code. Each block of 99-byte data is composed of a 3-byte header 44 and 96-byte data 41.

At the time of recording / reproducing a digital signal, the timing generation circuit 112 uses a clock generated by the oscillation circuit 113 as a reference and controls a control signal serving as a reference for signal processing and a processing timing of the digital signal processing circuit 111 by a predetermined position. Drum control circuit 10 synchronized with phase difference
4 are generated. In the drum control circuit 104,
As in the case of recording / reproducing an analog signal, control is performed such that the reference signal and the head position signal detected by the detector 103 have a predetermined phase. At the same time, a head switching signal is generated to control the head switching circuit 106.

FIG. 9 shows a configuration example of the timing generation circuit 112. In the figure, 211 is an edge detection circuit, 212 is a counter operating at a track cycle or an integral multiple thereof,
Reference numerals 213 denote decoders, each of which is generated by the oscillation circuit 113 and operates by a clock input from the input terminal 201. The decoder 213 decodes the output of the counter 212 and generates a timing signal as a reference for operation of the digital signal recording / reproducing circuit 111 and a reference signal for drum control. A timing signal serving as a reference for the operation of the digital signal recording / reproducing circuit 111 is output from an output terminal 205. The reference signal for drum control is output from output terminal 2
04 is output to the switching circuit 108. In the edge detection circuit 211, the head switching circuit 106
A signal having the same timing as the head switching signal or the head switching signal itself is input from the input terminal 203 to detect a falling edge or a rising edge. Then, the counter 212 is reset by the synchronization control signal input from the control circuit 114 via the input terminal 202 and the detected edge signal.

FIG. 10 shows the operation timing of the timing generation circuit 112, that is, the timing when the falling edge is detected by the edge detection circuit 211 in FIG. 9 and the counter 212 is reset. The analog reference signal is a reference signal for drum control at the time of analog signal recording and reproduction generated by the analog signal recording and reproduction circuit 109, and the digital reference signal is a signal for drum control at the time of digital signal recording and reproduction generated by the timing generation circuit 112. Is a reference signal.

The resetting of the counter 212, that is, the synchronization of the digital signal processing, is performed during the recording / reproducing mode of the analog signal, that is, when the drum is controlled by the analog reference signal output from the analog signal recording / reproducing circuit. At this time, the video head switching signal and the audio head switching signal are output at the timing shown in FIG. 10 in synchronization with the analog reference signal. In the timing generation circuit 112, the fall of the audio head switching signal while the synchronization control signal is at the H level, that is, at time A, the frame period of the audio head switching signal and the frame period of the digital signal recording / reproducing process match. By resetting the counter 212, the recording / reproducing processing timing of the digital signal recording / reproducing circuit 111 and the rotation of the drum 100 can be synchronized.

At this time, in the timing generation circuit 112, as shown in the figure, the phase of the digital reference signal has a phase difference of α in advance with respect to the phase of the recording / reproducing processing timing of the digital signal. In this way, after synchronization is performed at time A, the phase of the analog reference signal matches the phase of the digital reference signal. Even if the processing is changed and the reference signal is switched, the phase difference β between the reference signal and the head position signal is kept constant. As a result, there is no need to resynchronize the rotation of the drum 100 with the reference signal, and the recording or reproduction operation can be started immediately after the signal processing is switched. Also in the drum control circuit 104, the synchronization between the reference signal and the head position signal can be achieved by always having the phase difference β regardless of whether the recording signal is analog or digital. In this case, the audio head switching signal may be used as it is as the digital head switching signal as the head switching signal after the switching of the signal processing.

The phase difference α between the digital reference signal phase and the phase of the recording / reproducing processing timing of the digital signal is due to the mounting angle difference α of the magnetic head shown in FIG. The reproducing head is an analog audio signal recording / reproducing head 102a, 102b
This is because it is also used for For example, a digital signal recording / reproducing magnetic head 1 for recording / reproducing an analog video signal.
If 01a and 101b are used for both purposes, the operation timing of the timing generation circuit 112 is as shown in FIG. That is, the counter 212 is reset such that the frame period of the video head switching signal coincides with the frame period of the digital signal recording / reproducing process at the falling edge of the video head switching signal synchronized with the analog reference signal, that is, at time C. Then, the phase of the digital reference signal is made the same as the phase of the digital signal recording / reproducing processing, and the video switching signal is used as the head switching signal.
When the process is switched from the recording / reproduction of the analog signal to the recording / reproduction of the digital signal at the time point D, it is not necessary to re-synchronize the rotation of the drum 100 with the reference signal. Further, the recording / reproducing head of the digital signal is a magnetic head 1
01a, 101b, and 102a and 102b, the phase of the digital signal recording / reproducing processing timing and the phase of the digital reference signal are compared with the analog video signal recording / reproducing magnetic head and the digital signal recording / reproducing. If a signal is generated with a phase difference that is the same as the mounting angle difference of the magnetic head and synchronization processing is performed so that the phases of the analog reference signal and the digital reference signal match, the signal processing can be performed in analog as in this embodiment. It is possible to eliminate the need for re-synchronizing the rotation of the drum 100 and the reference signal when switching between digital and digital.

FIG. 12 shows the operation timing of the timing generation circuit 112 when the cycle of the reference signal is once per frame. In this case as well, the synchronization can be performed as in the case of FIG.

Here, the operation of the drum control circuit 104 will be described. FIG. 13 shows a configuration example of the drum control circuit 104. In the figure, 301 is a phase comparison circuit, 302 is a drive circuit, and 303 is a control signal generation circuit. Also, 31
1 is an up / down counter, 312 is a reference signal detection circuit, 313 is a comparison circuit, 321 is an input terminal for inputting a reference signal from the switching circuit 108, 322 is an input terminal for inputting a head position signal from the detection circuit 103, 323 is a drum. Output terminals 324 and 325 for outputting a control signal are output terminals for outputting a head switching signal to the head switching circuits 105 and 106, and 326 is an output terminal for outputting a control signal to the timing generation circuit 112.

In the drum control circuit 104, the switching circuit 10
8 and the phase of the head position signal detected by the detection circuit 103 and input from the input terminal 322, and the phase of the reference signal input from the input terminal 321.
1, the phase difference is detected, and a drum control signal is generated in the drive circuit 302 based on the comparison result. The drum control signal is generated so that the phase difference becomes a predetermined value, in this embodiment, β in FIG. The rotation is controlled. At the same time, a control signal such as a head switching signal is generated in the control signal generation circuit 303 and output from the output terminals 324, 325 and 326 to the head switching circuits 105 and 106 and the timing generation circuit 112, respectively.

FIG. 14 shows the operation timing of the phase comparison circuit 301 when a synchronization signal of an analog video signal is input from the switching circuit 108 as a reference signal during recording of an analog signal. FIG. 7A shows a synchronization signal of an analog video signal input from the input terminal 321, and this signal is input to the up / down counter 311. The output of the up / down counter 311 is operated to increase when the input signal from the input terminal 321 is at the H level, and to decrease when the input signal from the input terminal 321 is at the L level. Further, a maximum value and a minimum value are set in advance, and control is performed so that the count value does not exceed the maximum value and the minimum value. The output waveform of the up / down counter 311 is shown in FIG. Up / down counter 311
Is output to the reference signal detection circuit 312. When the input signal is higher than a predetermined level in the reference signal detection circuit 312, an H level signal is output,
If the signal is lower than the predetermined level, an L level signal is output, so that the vertical synchronizing signal portion of the analog video signal can be detected as a phase comparison reference signal. The phase difference is obtained by comparing the phase of the rising edge of the phase comparison reference signal with the phase of the rising edge of the head position signal input from the input terminal 322.

The above-described phase comparison circuit 301 sets the pulse width of the reference signal at the time of digital signal recording and reproduction generated by the timing generation circuit 112 to be equal to or greater than the vertical synchronization signal period of the analog video signal. It becomes possible to share. This will be described below. In the phase comparison circuit 301, when a signal having a narrow pulse width as shown in FIG. 15A is used as a reference signal at the time of digital signal recording / reproduction, the output of the up / down counter 311 is shown in FIG. A) and (b), and the reference signal detection circuit 312 cannot generate the phase comparison reference signal. However, by setting the pulse width of the reference signal to be equal to or longer than the vertical synchronization signal period of the analog video signal,
By setting the signal as shown in FIG. 9B, the output of the up / down counter 311 is changed to the signal shown in FIG.
As shown in (b), a phase comparison reference signal as shown in FIGS. (B) and (c) can be detected. Therefore,
In the timing generation circuit 112 according to the present embodiment, the pulse width of the reference signal used for recording and reproducing the digital signal is set to a width equal to or longer than the vertical synchronization signal period of the analog video signal, so that the phase comparison circuit 301 can be used. It can be shared between analog signal processing and digital signal processing.

Further, by keeping the number of revolutions of the drum during recording and reproduction of an analog signal and the number of revolutions of the drum during recording and reproduction of a digital signal coincide with each other, the phase shift of the reference signal at the time of switching can be further reduced. . When recording an analog video signal, it is necessary to match the number of revolutions of the drum with the frame period of the video signal. As described above, the same frame period, for example, 30 / 1.001 Hz is used. On the other hand, in the case of recording a digitally compressed video signal compressed by, for example, the MPEG method, there is no correlation between the compressed signal and the frame period, so that it is not necessary to synchronize the rotation number of the drum with the frame period. Absent. Therefore, for example, it is conceivable to set the frequency to 30 Hz which is easier to generate than the reference clock. However, in this case, even if the synchronization is performed at the time point A in FIG. 10, the phase difference between the analog reference signal and the digital reference signal is caused by the difference in the rotation speed until the time point B when the reference signal is switched. A gap will occur. This deviation increases as the time point A at which the synchronization process is performed and the time point B at which the process is switched are separated. In this case, the rotation speed of the drum during digital recording and reproduction is the same 30 / 1.001 Hz as during analog recording and reproduction. The phase relationship can be maintained even if the interval between the time point A at which the processing is performed and the time point B at which the processing is switched becomes long.

The synchronization may be performed a fixed time before the point of switching. For example, a digital signal recording / reproducing circuit 1
If it takes six tracks before the normal processing can be started after the synchronization, the synchronization may be performed six or more tracks before the point of switching. Also,
Synchronization may be performed at all times during recording and reproduction of analog signals, and the synchronization may be stopped before switching.

Switching between analog signal processing and digital signal processing is performed by the control circuit 114. For example, an analog / digital switch is prepared in the device, and the device is controlled in synchronization with an analog signal as an initial state of the device. When the user operates the switch, the synchronization described above is performed. And switching of signal processing may be performed. Further, the apparatus may be controlled in synchronization with an analog signal as an initial state of the apparatus, and may switch to digital signal processing when a digital signal input is detected during recording. In addition, a detection hole for discriminating between analog signal recording / reproduction and digital signal recording / reproduction is provided in the case of the magnetic tape to be used, and the hole is detected to switch the processing. If a horizontal synchronization signal is not detected, switching to digital signal processing may be used.

The frame period of the analog signal, 30/1.
When the frame period of the digital signal is set to 30 Hz with respect to 001 Hz, the interval between the point at which the synchronization processing is performed and the point at which the signal processing is switched is shortened.
The phase shift between the analog reference signal and the digital reference signal at the time of switching the signal processing can be further reduced. That is,
For example, as shown in FIG. 16, the digital signal processing timing is first synchronized at the falling point of the head switching signal after the synchronization control signal becomes H level, time E,
Until the time point F, the digital signal processing timing is resynchronized at each falling point of the head switching signal. By shortening the interval from the time point F at which the digital signal processing timing is finally synchronized to the time point G at which the signal processing is switched by this processing, the phase shift between the analog reference signal and the digital reference signal can be kept small.

In this case, the synchronization is performed at the time of switching.
It is desirable to perform as close as possible to maintain the phase relationship between the analog reference signal and the digital reference signal.

FIG. 17 shows an example of connection between the apparatus of the present embodiment and a digital broadcast receiver when recording and reproducing a digital compressed video signal as a digital signal to be recorded and reproduced in the present embodiment. 400 is a rotary head recording / reproducing apparatus shown in FIG. 1, 401 is a digital broadcast receiver, 402 is an antenna, and 403 is a receiver. 411 is a tuner,
412 is a selection circuit, 413 is a decoding circuit, and 414 is an interface circuit. After the digital broadcast signal received by the antenna 402 is demodulated by the tuner 411, the selection circuit 412 selects a desired digital compressed video signal. The selected digital compressed video signal is decoded by a decoding circuit 413 into a normal video signal, and
Is output to When the received signal has been subjected to a process such as scrambling, the decoding circuit 413 cancels the signal and performs a decoding process. When recording, the interface circuit 414 converts the data into packet format data of a predetermined number of bytes including a control signal such as time information and outputs the data. Then, the data is input from the input / output terminal 117 to the device 400 of the present embodiment and recorded. A digital compressed video signal and the like reproduced by the device 400 of this embodiment are output from the input / output terminal 117. The digital compressed video signal input from the interface circuit 414 performs the same processing as during normal reception, and is output to the receiver 403.

In the synchronous processing timing of the present embodiment, in FIG.
12 is reset and the timing of the digital recording / reproducing circuit is synchronized, but by loading a predetermined value to the counter 212 using an analog reference signal and a video head switching signal in the figure. Alternatively, the timing of the digital recording / reproducing circuit may be synchronized.
In this embodiment, the case where the processing is switched from the recording / reproduction of the analog signal to the recording / reproduction of the digital signal has been described. However, the same synchronization can be performed even when the recording / reproduction of a plurality of types of digital signals is switched. The same effect can be obtained.

[0039]

According to the present invention, when recording and reproduction are performed by switching processing from recording and reproduction of an analog video signal to recording and reproduction of a digital signal, a reference signal for drum control at the time of recording and reproduction of a digital signal is used as a digital signal recording and reproduction. A predetermined phase difference is given to the signal processing timing of the circuit in advance,
A signal is generated so as to have the same phase as the reference signal of the drum control at the time of analog signal recording and reproduction, and further, the timing of the reference signal is synchronized with the rotation phase of the drum, and then the signal processing is switched. The reference signal and the rotation of the drum can be kept synchronized before and after, that is, the recording or reproducing operation can be started instantaneously without the need for resynchronizing the drum when switching the signal processing. Further, by generating a reference signal for drum control at the time of digital signal recording / playback to be greater than the width of the reference signal for drum control at the time of analog signal recording / playback, the drum control circuit can be used for both analog signal processing and digital signal processing. Can be shared.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a rotary head recording / reproducing apparatus.

FIG. 2 is a diagram illustrating a configuration example of a drum 100 and a magnetic head of FIG. 1;

FIG. 3 is a drum control circuit 10 for recording and reproducing an analog signal.
FIG. 9 is a diagram showing an example of the operation timing of FIG.

FIG. 4 is a diagram showing an example of a recording pattern on a magnetic tape.

FIG. 5 is a diagram showing an example of a recording pattern of one track when recording a digital signal.

FIG. 6 is a diagram illustrating an example of a block configuration of each area.

FIG. 7 is a diagram illustrating a configuration example of ID information.

FIG. 8 is a diagram showing a configuration example of data of one track in a data recording area.

9 is a diagram illustrating a configuration example of a timing generation circuit 112 in FIG. 1;

FIG. 10 is a diagram illustrating an example of an operation timing of the timing generation circuit 112 in FIG. 1;

11 is a diagram illustrating an example of an operation timing of the timing generation circuit 112 in FIG. 1;

12 is a diagram illustrating an example of an operation timing of the timing generation circuit 112 in FIG.

FIG. 13 is a diagram illustrating a configuration example of a drum control circuit 104 in FIG. 1;

14 is a diagram illustrating an example of an operation timing of the phase comparison circuit 301 in FIG.

FIG. 15 is a diagram illustrating an example of an operation timing of the phase comparison circuit 301 in FIG. 13;

FIG. 16 is a diagram illustrating an example of an operation timing of the timing generation circuit 112 in FIG. 1;

FIG. 17 is a diagram illustrating a connection example of a rotary head recording / reproducing device of the present embodiment and a digital broadcast receiver.

[Explanation of symbols]

100 ... drum, 101a, 101b, 102a, 10
2b: magnetic head, 103: detection circuit, 104: drum control circuit, 105, 106: head switching circuit, 107,
108: switching circuit, 109: analog signal recording / reproducing circuit, 110, 113: oscillation circuit, 111: digital signal recording / reproducing circuit, 112: timing generation circuit, 114
... Control circuit, 118 ... Capstan, 119 ... Magnetic tape, 211 ... Edge detection circuit, 212 ... Counter, 21
Reference numeral 3 denotes a decoder, 301 denotes a phase comparison circuit, 302 denotes a drive circuit, and 303 denotes a control signal generation circuit.

Claims (7)

[Claims] A first signal for recording or reproducing a first signal.
Recording / reproducing circuit, a second recording / reproducing circuit for performing recording / reproducing processing of a second signal, and recording / reproducing of a recording signal generated by the first recording / reproducing circuit on a magnetic recording medium. A drum on which a first magnetic head and a second magnetic head for recording or reproducing a recording signal generated by the second recording / reproducing circuit on a magnetic recording medium are attached; When performing recording or reproduction, the rotation of the drum is controlled based on the first reference signal generated by the first recording / reproduction circuit, and when performing recording or reproduction of the second signal, A drum control circuit for controlling rotation of the drum based on a second reference signal generated by the second recording / reproducing circuit, wherein the second recording / reproducing circuit comprises: A second reference signal and the drum A rotating head recording means for generating the second reference signal such that a phase relationship between the rotation and the rotation of the drum is substantially the same as a phase relationship between the rotation of the first reference signal and the rotation of the drum; Playback device. 2. The timing generating means synchronizes the second reference signal with the rotation of the drum when the rotation of the drum is controlled in synchronization with the first reference signal. 2. The recording / reproducing apparatus according to claim 1, wherein: 3. The rotary head recording / reproducing apparatus according to claim 1, wherein said first signal is an analog video signal, and said second signal is a digital signal. 4. A first signal for recording or reproducing a first signal.
Recording / reproducing circuit, a second recording / reproducing circuit for performing recording / reproducing processing of a second signal, and recording / reproducing of a recording signal generated by the first recording / reproducing circuit on a magnetic recording medium. A drum on which a first magnetic head and a second magnetic head for recording or reproducing a recording signal generated by the second recording / reproducing circuit on a magnetic recording medium are attached; When performing recording or reproduction, the rotation of the drum is controlled based on the first reference signal generated by the first recording / reproduction circuit, and when performing recording or reproduction of the second signal, A drum control circuit for controlling rotation of the drum based on a second reference signal generated by the second recording / reproducing circuit, wherein the second recording / reproducing circuit comprises: At least before the second reference signal A recording / reproducing apparatus for a rotary head, comprising: timing generating means for generating a pulse having a pulse width equal to or greater than that of the first reference signal. 5. The timing generating means according to claim 1, wherein a phase relationship between said second reference signal and said drum rotation is substantially the same as a phase relationship between said first reference signal and said drum rotation. 5. The recording / reproducing apparatus according to claim 4, wherein the second reference signal is generated. 6. The timing generating means synchronizes the second reference signal with the rotation of the drum when the rotation of the drum is controlled in synchronization with the first reference signal. The rotary head recording / reproducing apparatus according to claim 4 or 5, wherein 7. The system according to claim 1, wherein the first signal is an analog video signal, the second signal is a digital compressed video signal,
7. The rotating head recording / reproducing apparatus according to claim 4, wherein the first reference signal is a vertical synchronization signal detected from the analog video signal.