JPS632107A - Rotary head type pcm recording and reproducing device - Google Patents

Abstract

PURPOSE:To record a data on an accurate position at after-recording by providing a sub recording magnetic head, a means reproducing a data block synchronizing signal in a digital data reproduced from a magnetic tape by a main recording/reproducing magnetic head at after-recording and a means controlling the recording position of the after-recording data. CONSTITUTION:Plural main recording/reproducing magnetic heads 16, 18 act like reproducing heads at after-recording, plural sub recording/reproducing magnetic heads 20, 22 act like recording heads, and the magnetic heads scan the upper part of the magnetic tape 12. The digital data recorded on the magnetic tape is reproduced by the main recording/reproducing head is reproduced and the data block synchronizing signal is discriminated from the reproduced digital data. Then the recording position of the data recorded by plural sub recording/reproducing magnetic heads, that is, the after-recording data is controlled based on the data block synchronizing signal. Thus, the data is recorded at an accurate position at the post-recording.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotary head type PCM recording/playback device, and in particular to a rotary head type PCM recording/reproducing device, such as an R-DAT (rotating head type digital audio tape recorder). The present invention relates to a rotating helad type PCM recording and reproducing device having a data area.

(Prior art) An example of after-recording (hereinafter referred to as "dubbing") technology in R-DAT is, for example, Japanese Patent Application Laid-Open No. 60-656.
It is disclosed in the publication No.

In this prior art, the mounting of the reproducing head on the rotating cylinder is offset by one track so that it can scan the track in advance of the recording head.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, the mounting position on the rotary cylinder is simply set so that the reproducing head can scan ahead of the recording head, so it is difficult to avoid problems such as elongation of the magnetic tape. Due to physical deformation, it was not always possible to accurately record post-recording data at the predetermined position read by the playback head.

If the dubbing data, that is, the time-compressed audio signal is not recorded at a predetermined position, 1. Since dubbing involves overwriting and erasing, the previous time-compressed audio signal may remain at the front or rear of the post-recorded time-compressed audio signal. In this case, when playing back the magnetic tape, that is, when digital signal processing is performed on the time-compressed audio signal, the playback start point or playback end point of the playback digital data may be misjudged, resulting in distortion of the playback signal. .

Therefore, the main object of the present invention is to develop a rotating head type PCM that can record at an accurate position during post-recording.
An object of the present invention is to provide a recording/playback device.

(Means for Solving the Problems) Simply put, the present invention provides a rotary head drum, a plurality of main recording and reproducing heads provided on the rotary head drum, which operate as recording heads during recording and as playback heads during post-recording. Magnetic heads, rotating heads A plurality of sub-recording/reproducing magnetic heads are provided on the drum and operate as playback heads during recording and as recording heads during post-recording. Rotary head type PCM recording comprising means for reproducing a data block synchronization signal and means for controlling recording positions of post-record data by a plurality of sub-recording/reproducing magnetic heads based on the reproduced data block synchronization signal. It is a playback device.

(Function) During post-recording, the plurality of main recording/reproducing magnetic heads operate as playback heads, and the plurality of sub-recording/reproducing magnetic heads operate as recording heads. These magnetic heads scan the magnetic tape. Therefore, with the main recording/reproducing magnetic head,
Digital data recorded on the magnetic tape is played back. A data block synchronization signal is then discriminated from the reproduced digital data. Thereafter, based on the data block synchronization signal, the recording position of the data recorded from the 7th to the plurality of sub-recording/reproducing magnetic fields, that is, the recording position of the post-recording data is controlled.

(Effects of the Invention) According to the present invention, data recording positions by a plurality of sub-recording/reproducing magnetic heads can be controlled based on the reproduced data block synchronization signal, so data can be recorded at accurate positions during post-recording.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

(Example) FIG. 1 is a block diagram showing one embodiment of the present invention.

The PCM recording and reproducing apparatus 10 of this embodiment is shown as an R-DAT using, for example, an audio cassette. A portion of the mounted magnetic tape 12 is wrapped onto the side of the rotating head drum 14 at an angle of just over 90''.

As shown in the side view of FIG. 2, the rotary head drum 14 is provided with four magnetic heads: main recording/reproducing magnetic heads 16 and 18 and sub-recording/reproducing magnetic heads 20 and 22.

As shown in FIG. 2, the main recording/reproducing magnetic heads 16 and 18 are arranged on the same plane on a straight line centered on the center 0. However, since the main recording/reproducing magnetic heads 16 and 18 scan different tracks, their azimuth angles are different in consideration of the influence of leakage magnetic flux. Sub-recording/reproducing magnetic head 20
and 22 are also on the same plane, on a straight line centered on center 0, and at 9 with respect to the main recording/reproducing magnetic heads 16 and 18.
0'' position. Then, the sub-recording/reproducing magnetic head 2
The azimuth angles of 0 and 22 are also different.

Note that the main recording/reproducing magnetic heads 16 and 18 and the sub-recording/reproducing magnetic heads 20 and 22 are provided on different planes. As will be described later, the same trunk scanned by the main recording/reproducing magnetic head 16 or 18 during recording or post-recording is later scanned by the auxiliary recording/reproducing magnetic head 20 or 22.
This is so that it can be followed and scanned.

The main recording/reproducing magnetic heads 16 and 18 operate as a recording head during recording and as a reproducing head during post-recording. The sub-recording/reading magnetic heads 20 and 22 operate as reproducing heads during recording and as recording heads during after-recording. That is, during post-recording, the main recording/reproducing magnetic head 1
After-recording data is written again to the track that has been reproduced by No. 6 by the sub-recording/reproducing magnetic head 20. Similarly, the sub-recording/reproducing magnetic head 22 writes, for example, post-record data on the track scanned by the main recording/reproducing magnetic head 18.

Note that during post-recording, the main recording/reproducing magnetic heads 16 and 18 also operate as reproducing heads for reproducing pilot signals for controlling the running of the magnetic tape 12.

Returning to FIG. 1, a rotary transformer 28 is provided on an extension of the rotating shaft 26 to which the rotating head drum 14 is fixed. This low retransistor 28 is connected to the magnetic head 16.
22, or extract signals read from the magnetic tape 12. The input/output terminal of the low retransistor 28 is a movable contact terminal a of a switch 30 for switching between normal recording and dubbing.
and b. A signal from the movable contact terminal a is derived by switching the fixed contact terminal C, and this fixed contact terminal C is commonly connected to a fixed contact terminal f from which the signal from the movable contact terminal A is derived by switching the switch. It is connected to the output terminal of the recording amplifier circuit 32. An adder circuit 34 is connected to the input terminal of the amplifier circuit 32, and a PCM modulation circuit 36 and a pilot signal generation circuit 38 are connected to the adder circuit 34.

One input terminal of the PCM modulation circuit 36 is a terminal for inputting an audio signal. This PCM modulation circuit 36 is
During post-recording, it is controlled by a delay signal based on a data block synchronization signal, which will be described later. During normal recording, a signal detected in accordance with the rotation of the rotary head drum 14 is input to this control input of the PCM modulation circuit 36. For that purpose, this control input terminal is connected to the movable contact terminal g of the switch 40. One fixed contact terminal of the switch 40 is connected to an output terminal of a delay circuit 42 that outputs the above-described delayed signal.

An input terminal of the delay circuit 42 is connected to an output terminal of a digital signal processing circuit 44 . A reproduced signal passed through a regenerative amplifier circuit 46 is applied to the input of this digital signal processing circuit 44 . Incidentally, as shown in FIG. 5, each of these reproduction signals is a data block synchronization signal (SYN
C), block address (BLOCK ADDRES)
It is formed from n blocks including S) and time compressed audio signal data (DATA). The data block synchronization signal output from the digital signal processing circuit 44 is
It is formed based on the data block synchronization signal (SYNC) of the first block of the time compressed audio signal shown in FIG. The digital signal processing circuit 44 extracts a data block synchronization signal from the supplied reproduced signal and supplies the synchronization signal as a trigger input to the delay circuit 42 . The output terminal of the regenerative amplifier circuit 46 is also connected to an ATF signal generation circuit 48 .

The output terminal of the ATF signal generation circuit 48 is connected to one input terminal of the addition circuit 50. The output terminal of the speed setting circuit 52 is connected to the other input terminal of the adder circuit βO. The output of the adder circuit 50 is given to a motor drive circuit 54, and the motor drive circuit 54 forms, for example, a phase locked loop (PLL) based on this given signal to drive a capstan motor 56. Outputs a drive signal for When the capstan 58 is driven by the capstan motor 56, a tensile force is applied accordingly, and the magnetic tape 12 runs in the direction of the arrow.

Specifically, the rotation speed of the capstan 58 is detected by a frequency generator coil (FC coil) 60.

The signal detected by the FC coil 60 is provided to a frequency discriminator 62. The signal discriminated by the frequency discriminator 62 is input to the adding circuit 50 via the speed setting circuit 52. That is, the rotation of the capstan 58 is detected by the FC coil 60 and fed back to the adding circuit 50 . This signal is generated by the ATF signal generation circuit 4.
This is a signal for performing a control operation so that the capstan 58 rotates in accordance with the signal output from the capstan 8.

On the other hand, the output terminal of the phase control circuit 64 is connected to the fixed contact terminal i of the switch 40 described above.

The signal from the phase control circuit 64 is also applied to the input terminal of the above-mentioned biloft signal generation circuit 38. An input terminal of this phase control circuit 64 is connected to an output terminal of a phase adjustment circuit 66 . The rotational speed of the rotating head drum 14 driven by the drum motor 24 is detected by a pulse generator coil, (PG coil) 72. The pulse signal from this PC coil 72 undergoes phase adjustment in a phase adjustment circuit 66, and is applied as an RF switching pulse to a phase comparator 68 and the above-mentioned phase control circuit 64. Therefore, the drum motor 24 for rotating the rotary head drum 14 is controlled by the RF switching pulse of the phase adjustment circuit 66 and the reference signal (reference pulse).

In addition, a phase comparator 6 is connected to the output terminal of the phase adjustment circuit 66.
One input terminal of 8 is connected. A reference signal for driving the drum motor 24 is supplied from the other input terminal of the phase comparator 68 .

The output terminal of the phase comparator 68 is connected to the input terminal of a motor drive circuit 70 for driving the drum motor 24.

On the other hand, the RF switching pulse of the phase adjustment circuit 66 is applied not only to the phase comparator 68 but also to the phase control circuit 64. The RF switching pulse whose phase is controlled by the phase control circuit 64 is given to the viroft signal generation circuit 38, and is also given to the PCM modulation circuit 36 when the movable contact of the switch 40 is switched to the fixed contact i side. , the operation during recording will be explained. In FIG. 1, during recording, the two movable contacts of the switch 30 are switched to fixed contact terminals d and f. switch 4
The movable contact of 0 is switched to the fixed contact terminal i side.

When the reference pulse is applied to the phase comparator 68 and the drum motor 24 is driven, the rotary head drum 14 rotates. The rotating head drum 140 rotation speed is the PC coil 72
The signal is detected by the phase adjustment circuit 66 and converted into an RF switching pulse. This RF switching pulse is applied to one input terminal of the phase comparator 68, and is also applied to the pilot signal generation circuit 38 and the PCM modulation circuit 36 via the phase control circuit 64. That is, since the movable contact of the switch 40 is switched to the fixed contact terminal i, the output signal of the phase control circuit 64 is switched to the fixed contact terminal i.
The signal is applied to one input terminal of the PCM modulation circuit 36 through the movable contact terminal g.

When an audio signal is input to the other input terminal of the PCM modulation circuit 36, that is, when a signal to be recorded is input,
Based on the output signal of the phase control circuit 64, the audio signal is P
CM modulated. That is, the audio signal is converted into a pulse train compressed into a time equal to the scan time of the recording/remagnetic heads 16 and 18 on the magnetic tape 12.

- On the other hand, the phase control circuit 64 on the third day of the pilot signal generation circuit
When a signal is output from the pyro-/) signal generating circuit 38, the pilot signal is output to the adding circuit 34. Therefore, the PCM-modulated audio signal is combined with the pilot signal in the adder circuit 34 and amplified in the amplifier circuit 32. The amplified output of the amplifier circuit 32 is transmitted to the fixed contact terminal f and the movable contact terminal of the switch 30 as well as to the low retransformer 2.
8 to the recording/remagnetic heads 16 and 18. Accordingly, diagonal track patterns 74 and 76 are formed alternately on magnetic tape 12, as shown in FIG. The trunk pattern 74 is formed by scanning the main recording/reproducing magnetic head 16, and the track pattern 76 is formed by scanning the main recording/reproducing magnetic head 18.

The trunk patterns 74 and 76 are composed of a time-compressed audio signal recording area 74a or 76a provided in the center of the magnetic tape 12, respectively, and pilot signal recording areas 74b or 76b provided on both sides of this area. Therefore, the amplified output of the PCM modulation circuit 36 is written into the audio signal recording areas 74a and 76a. The output of the pilot signal generation circuit 38 is amplified and magnetically recorded in the biloft signal recording areas 74b and 76b.

The track pattern 74 formed by the main recording/reproducing magnetic head 16 is scanned by the side edge re-magnetic head 20, and the magnetically recorded data is read out. Similarly, the track pattern 76 formed by the main magnetic recording/reproducing head 18 is scanned by the side edge magnetic recording/reproducing head 22, and the magnetically recorded data is read out.

The data read by the side edge remagnetic heads 20 and 22 is applied to the amplifier circuit 46 via the low retransformer 2B and the switch 30. In other words, when recording, 2
The two movable contact terminals are switched to fixed contact terminals d and f. Therefore, the signal from the movable contact terminal a is guided to the fixed contact terminal d.

The signal of the amplifier circuit 46, that is, the side edge remagnetization head 20
The signal read out and amplified by PCM demodulation circuit 49 . It is applied to the ATF signal generation circuit 48 and the digital signal processing circuit 44. However, even if the signal from the amplifier circuit 46 is input manually to the digital signal processing circuit 44,
Since the movable contact of the switch 40 has been switched to the fixed contact terminal i side, the output of the digital signal processing circuit 44 has no meaning.

When the signal from the amplifier circuit 46 is applied to the PCM demodulation circuit 49, the pulse is converted back into an audio signal, and the reproduced audio signal is output from the output terminal. By outputting an audio signal from the output terminal of the PCM demodulation circuit 49, it is possible to monitor that the audio signal applied to the PCM modulation circuit 36 is recorded in the audio signal recording areas 74a and 74b of the magnetic tape 12.

In the ATF signal generation circuit 48, as shown in FIG.
The pilot signals recorded in the pilot signal recording areas 74b and 76b of the magnetic tape 12 are extracted.

The pilot signal extracted by the ATF signal generation circuit 48 is passed through the addition circuit 50 to the motor drive circuit 54.
given to. The motor drive circuit 54 drives the capstan motor 56 based on this applied signal. When the capstan 58 is rotated by the drive of the capstan motor 56, that is, when the magnetic tape 12 runs in the direction of the arrow, the rotational speed of the capstan 58 is detected by the FC coil 60.

The detection output of the FC coil 60 is fed back to the addition circuit 50 through the frequency discriminator 62 and the speed setting circuit 52. In other words, the capstan 5 is connected to the FG coil 60.
By detecting the rotational speed of the magnetic tape 8, a tracking error signal of the magnetic tape 12 is provided to the adding circuit 50.

Therefore, when a tracking error signal is input, A
A correction operation is performed so that the capstan motor 56 is driven based on the pilot signal of the TF signal generation circuit 48. That is, during recording, the running of the magnetic tape 12 is controlled by the already recorded biloft signal.

Next, the operation of dubbing will be explained. During dubbing, in FIG. 1, the two movable contacts of the switch 30 are switched to the fixed contacts C and f, and the movable contact of the switch 40 is switched to the fixed contact side.

During post-recording, the main recording/remagnetic heads 16 and 18 operate as reproducing heads, and the side edge remagnetic heads 20 and 22 operate as recording heads.

During dubbing, as during recording, when the rotary head drum 14 is rotated by a reference pulse applied to the comparator 68, the already recorded time-compressed audio signal and biloft signal are read out by the main recording/reproducing magnetic heads 16 and 18. The read time compressed audio signal and pilot signal are sent to the low retransistor 28. The amplifier circuit 46 is connected through the movable contact terminal e and the fixed contact terminal e of the switch 30.
given to. The amplified output amplified by the amplifier circuit 46 is
As in the case of recording, the ATF signal generation circuit 48 is applied to the digital signal processing circuit 44 and the PCM demodulation circuit 49.

When the amplified output from the amplifier circuit 46 is given to the ATF signal generation circuit 48, the ATF signal is extracted and the running of the magnetic tape 12 is controlled at the same speed as when the already recorded data was recorded.

- On the other hand, when the amplified output is given from the amplifier circuit 46 to the digital signal circuit 44, a data block synchronization signal is output from the digital signal processing circuit 44, as shown in FIG. The timing at which this block synchronization signal is output is, in FIG. 3, when the main recording/reproducing magnetic head 16 finishes scanning the biloft signal recording area 74b and starts scanning the time-compressed audio signal recording area 74a.

In FIG. 4, R output from the phase adjustment circuit 66
When the F switching pulse is on, the first half time t is the time when the main recording/reproducing magnetic head 16 is scanning the track 74, and the second half time t2 is the time when the side edge re-magnetic head 20 is scanning the track 74.
is also the time to scan track 74. Time 1. Among these, times t and t4 are the times for scanning the pilot signal recording area 74b, and time t4 is the time for scanning the time-compressed audio signal recording area 74a. Therefore, when the scanning of the pilot signal recording area 74b is completed, a data block synchronization signal is outputted from the digital signal processing circuit 44 as shown in FIG.

Thereafter, a delay signal is output from the delay circuit 42 after a time t0. Note that when the delay signal is output from the delay circuit 42, the position of the side edge remagnetic head 20 is adjusted to scan the pilot signal recording area 74b. After that, the time-compressed audio recording signal recording area 74a has been reached. The delay signal output from the delay circuit 42 is applied to one input terminal of the PCM modulation circuit 36 through the fixed contact terminal and the movable contact terminal g of the switch 40. Then, PCM modulation is performed and time 1. The time-compressed audio signal is sent to the fixed contact terminal C of the switch 30 at time t6.
1 movable contact terminal a and the low retransistor 28, magnetically recorded from the side edge remagnetic head 20 to the time compressed audio signal recording area 74a. That is, the time-compressed audio signal recording area 74 scanned and read by the main recording/reproducing magnetic head 16 prior to scanning by the side edge re-magnetic head 20
After-recording data is recorded accurately at position a.

Note that the magnetic tape 12 has a pilot signal recording area 74.
Since the traveling is controlled based on the recorded data of b, the biloft signal generation circuit 38 does not operate during post-recording.

Therefore, the time-compressed audio signal of the PCM modulation circuit 36 is directly given to the amplifier circuit 32 without generating a pilot signal in the adding circuit 34.

In this way, even if the data block synchronization signal of the first block becomes undetectable due to a dropout of the magnetic tape 12, etc., if the data block synchronization signal of any block can be detected, the detected data block synchronization Delay circuit 42 based on the timing of the signal
It goes without saying that the post-recording data can be recorded accurately by changing the timing of the delayed signal from the recording station.

Furthermore, although the scanning time of the main recording/reproducing magnetic head 18 and the side edge remagnetizing head 22 is not shown in FIG.
The second scan is performed when the RF switching pulse output from the phase adjustment circuit 66 becomes low level. When the RF switching pulse is low, the track being scanned is trunk 76 in FIG. At this time as well, the running of the magnetic tape 12 is controlled based on the biloft signal magnetically recorded in the pilot signal recording area 76b, and the dubbing data is transferred from the side edge remagnetic head 22 to the time compressed audio signal recording area 76b.
6a.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a side view showing the arrangement of the main recording/reproducing magnetic head and the side edge re-magnetic head provided on the rotary head drum. FIG. 3 shows the trunk format of magnetic tape. FIG. 4 shows a timing chart during dubbing. FIG. 5 shows the data format of a time-compressed audio signal. In the figure, 12 is a magnetic tape, 14 is a rotating head drum, 16.18 is a main recording/reproducing magnetic head, 20.22 is a side edge remagnetic head, 36 is a PCM modulation circuit, 42 is a delay circuit, and 44 is a digital signal processing Shows the circuit. Patent applicant Sanyo Electric Co., Ltd. agent Patent attorney Yama 1) Yoshihito (and 1 other person) Go 2 Figure 1 Muro ε1) 371 A6b =

Claims (1)

[Scope of Claims] 1. A rotating head drum, a plurality of main recording/reproducing magnetic heads provided on the rotating head drum and operating as recording heads during recording and operating as playback heads during after-recording, provided on the rotating head drum. , a plurality of auxiliary recording/reproducing magnetic heads that operate as playback heads during recording and as recording heads during after-recording, and reproducing data block synchronization signals in digital data reproduced from the magnetic tape by the main recording/reproducing magnetic head during after-recording. and means for controlling recording positions of after-recording data by the plurality of sub-recording/reproducing magnetic heads based on the reproduced data block synchronization signal. 2. The rotary head type PCM recording/reproducing apparatus according to claim 1, wherein the means for controlling the recording position includes means for controlling the timing of applying the after-recording data to the sub-recording/reproducing magnetic head. 3. The means for controlling the timing includes means for outputting a delayed signal after a predetermined time based on the data block synchronization signal, and means for outputting the time-compressed after-recording data to the sub-recording/reproducing magnetic head in response to the delayed signal. A rotary head type PCM recording and reproducing apparatus according to claim 1, further comprising means for providing the same.