JPS6267703A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the function of PCM reproduction and simultaneous reproduction by means of an additional head by using a PCM reproduction head and a simultaneous reproduction head in common and providing the head on a pedestal deviated in the track direction. CONSTITUTION:Since the head is fitted on the pedestal possible for deviation, the pedestal is deviated to be at position of preceding reproduction to the video head at PCM reproduction and restored to the succeeding reproduction to the video head at the simultaneous reproduction. Since the device is constituted so as to deviate the head in the direction crossing the track, the function of both the PCM reproduction and the simultaneous reproduction is realized by adding one head. Further, the preceding reproduction is selected as the normal position and the succeeding reproduction is the deviated position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a helical scanning magnetic recording and reproducing device, in particular, a PCM audio signal area is provided on the extension of a video track, and a video signal and a PCM audio signal are simultaneously recorded. This invention relates to a reproduction device.

Conventional technology In a magnetic recording and reproducing device for video signals and PCM audio signals, which allocates a PCM audio area on the extension of a video track and records and reproduces a PCM audio signal using a video head in that area, the video signal and PCM audio signal are In order to match the phase (timing) with the audio signal, a head for playing the PCM rack is provided separately from the video head, and this PCM playback head is arranged so as to play back a track position several tracks ahead. ing.

On the other hand, in magnetic recording/reproducing devices, recording errors often occur due to head clogging, but to avoid this, a playback head is installed immediately after the recording head so that playback can be monitored while recording. There is something. This is especially true for broadcasting station equipment that requires reliability. By the way, in order to satisfy the PCM playback function as described above, a PCM playback head is required in addition to the video head. Since this PCM head is installed in a position preceding the video head, it cannot be used for simultaneous playback (monitoring).Therefore, in order to satisfy both PCM playback and simultaneous playback functions, additional need to be added.

Problems to be Solved by the Invention In order to satisfy both PCM playback and simultaneous playback, two heads (total of four heads when considering both the A channel and B channel) are added in addition to the video head. However, an increase in the number of heads attached to the rotary cylinder is unfavorable in terms of processing accuracy and results in a decrease in yield.

Furthermore, it becomes difficult to secure an appropriate head mounting space. Particularly in VTRs (magnetic recording and reproducing devices) for broadcasting stations, since a rotary-rad type erase head is attached to the cylinder, securing a mounting position for a new head is a serious problem.

Means for Solving the Problems The present invention is characterized in that the head for PCM reproduction and the head for simultaneous reproduction are the same head, and the head is mounted on a pedestal that can be deflected in the track direction. It is something.

Effects According to the above configuration of the present invention, since the head is mounted on the pedestal that can be deflected, during PCM playback, the head is deflected to the position of the preceding playback with respect to the video head, and during simultaneous playback, the head is deflected to the position of the preceding playback. , the video head is returned to the backward playback position. By configuring the head to be deviated in the direction across the track in this manner, both the functions of PCM reproduction and simultaneous reproduction can be realized by adding one head. Note that the normal position may be used during the preceding reproduction and the offset position may be used during the subsequent reproduction.

Embodiment FIG. 1 is a top view showing an embodiment of the present invention, showing the arrangement of a head attached to a cylinder. The erasing head performs an erasing operation before recording, 60 degrees ahead of the recording/reproducing head. The recording/reproducing head records video signals and PCM signals and reproduces video signals. During normal standard playback, the PCM head u deviates to the preceding playback position and plays back the preceding PCM area, and during simultaneous playback, it returns to the neutral position and outputs the video signal, P
Plays back (monitors) CM signals. The PCM signal during this simultaneous reproduction is demodulated and output with a phase delayed with respect to the video signal.

FIGS. 2(5) and 2(B) are front views showing the head deviation state in the standard playback mode and the simultaneous playback mode. 2. is the head mounting height correction value based on the 60° head mounting phase difference. Therefore, immediately after the erasing (RE) head scans, the recording/reproducing (It/P) head scans, so that both of them scan the same track. The same holds true for the reproduction (R/P) head and deflection (DT) head 1,1 in the simultaneous reproduction mode shown in (B).

On the other hand, 22 indicates the preceding position with respect to the reproduction (R/P) head. At this time as well, correction for the 60° slow phase is included, and the total leading amount (with respect to the R/P head) is 20% field. The amount of advance from the position of the deflection (DT) head during simultaneous playback is fi, +F! 2=3 fields. Here, the deflection head is provided on a pedestal of a piezo element that is deflected by application of a voltage, and is fixed to the cylinder by this pedestal.

FIG. 3 shows the scanning trajectories of these heads on the tape pattern.

FIG. 4 is a timing chart showing the process of signal processing during PCM recording and reproduction. The audio signal is divided into fields (gradient) and is sampled, PCM encoded, and time compressed (at the PCM signal writing timing of q, the PC
Recorded in area M.

In the playback mode, the preceding playback head reads the PCM signal at the timing of CI], (Fl, and the time expansion and PCM decoding are performed and demodulates the audio signal at timing (5) and ■.■', ■' becomes.

FIG. 6 is a block diagram showing the configuration of this embodiment. Audio input and video input signals are processed and recorded by passing a recording current through a recording/reproducing (R/P) head 3, 4 via a switch 1.2. In playback mode, the video signal system is amplified by the signals from the recording/reproducing (R/P) heads 3, 4 (passing through switch 1.2) and directed to switch 7.

) and the signals from the deflection (DT) heads 5 and 6 (amplified and guided to the switch 7) are selected by the switch 7, and the piezo elements on the bases of the demodulation rads 5 and 6 are connected to the control circuit 8.9. A voltage nl is applied, and the deviation between advance reproduction and simultaneous reproduction is switched according to the voltage value nl.

Note that it is also possible to perform special reproduction such as methyl, slow, cue, and review by fully utilizing the deflection head (not shown).

Figure 6 (formula shows that the video system is separated into a Y signal and a C signal, and is recorded and reproduced using separate heads.nl, and the PCM system is CHl,
FIG. 6 is a front view showing the configuration of a cylinder head when recording and reproducing are performed independently of CH2.

Moreover, FIG. 6(B) is a turn diagram of tape recording at that time.

In this embodiment, the number of heads is doubled, so the space-saving effect of the head mounting position of the present invention is extremely significant. The circuit configuration for switching between normal playback and simultaneous playback monitor is the same as the configuration shown in FIG. This was achieved with only one additional head and was limited to n
The head can be easily mounted on a cylinder with a small area.

In particular, in the case of a Y/C separation type VTR in which the number of heads is doubled, the effect becomes even more remarkable.

Further, not only the effects related to the cylinder configuration but also the increase in the number of head amplifiers and their control circuits corresponding to the number of heads can be minimized, so the design is easy.

[Brief explanation of drawings]

FIG. 1 is a top view of a cylinder according to an embodiment of the present invention, and FIG.
Figures (8) and (to) are front views of the cylinder, Figure 3 is a tape pattern diagram, Figure 4 is a time chart showing the process of recording and reproducing PCM signals, and Figure 6 is a diagram showing the configuration of this embodiment. A block diagram of FIG. 6 is a front view of a cylinder of the YC separation recording system, and FIG. 6 (b) is a tape pattern diagram thereof. 1.2... switch, 3, 4... recording/playback (R/P) head, 5. θ...Deflection (DT) head, 7...Switch, 8, 9...D
T head control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure #, To the shoe head i 艮^, To CVr 1 Do 2 Figure 2 Rε R/p DT Hair Head Head Figure 3 Figure 5

Claims (1)

[Claims] Video signal and PC on the video track or its extension
A recording/reproducing head for recording the M signal and reproducing the recorded video signal, and a deflection head which is provided separately from the recording/reproducing head and can be deflected in a direction across the track, are provided, and a standard reproduction mode is provided. Sometimes, the deflection head is deflected to a track position that can be reproduced in advance with respect to the recording/reproducing head to reproduce the PCM signal, and in a simultaneous reproduction mode, the deflection head is deflected to a track position that can be reproduced in a trailing manner with respect to the recording/reproducing head. A magnetic recording/reproducing device characterized in that it is configured to reproduce a video signal or a PCM signal by deflecting a head.