JPS6025054A - Reproducing device - Google Patents

Abstract

PURPOSE:To obtain a corresponding suitable audio signal by any reproducing method when a video signal is reproduced by providing the 1st reproducing means which reproduces the video signal on a medium, the 2nd reproducing means which reproduces the audio signal on the medium, and a storage means which stores the audio signal for a specific period. CONSTITUTION:Video signals reproduced by heads 6 and 7 are supplied to a head switching circuit 28 through terminals P of recording/reproduction changeover switches 24 and 26 and made into a continuous signal by the circuit 28. The signal is then reconverted to the original signal format by a video signal reproduction processing circuit 30 and outputted from a terminal 32. The audio signal reproduced by a head 5, on the other hand, is supplied to a waveform shaping circuit 42 through a recording/reproduction changeover switch 8 and a preamplifier 40 and made into the original signal by the circuit 42. This signal is outputted from an audio output terminal 48 through the terminal A of a changeover switch 44 and a regenerative amplifier 46. The changeover switch 44 is controlled by a system controller 52 according to a mode selected by a mode selector 50 such as an operation switch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a reproducing apparatus, and particularly to an apparatus for reproducing a video signal and an audio signal recorded on the same recording medium.

(Description of Prior Art) Conventionally, a video signal and an audio signal are recorded on a recording medium to be reproduced by this type of apparatus so as to correspond to each other. For example, in a magnetic recording/reproducing device (hereinafter referred to as VTR) that records video signals on a magnetic tape by sequentially forming diagonal tracks using a rotating head, an audio track is provided in the longitudinal direction at the end of the tape, and In some cases, an audio signal is recorded in correspondence with the video signal on the track, and in others, the video signal and audio signal are mixed and recorded on the diagonal track.

Incidentally, in recent years, the above-mentioned VTRs generally have so-called variable speed playback functions such as still image playback, slow motion playback, and high speed search playback. However, it is difficult to reproduce audio signals when performing such variable speed reproduction. For example - V with an audio track
In TR, the relative speed between the fixed head for audio signal reproduction and the tape changes, making it impossible to obtain a reproduced audio signal. Further, even in a VTR in which a video signal and an audio signal are mixed and recorded on diagonal tracks, the reproduced audio signal becomes discontinuous, so that a reproduced audio signal cannot be obtained. Therefore, when variable speed reproduction is performed in a scene such as a conversation, for example, there is a drawback that it is impossible to determine which scene is being reproduced.

Also, during variable speed playback on such a conventional VTRK,
If you want to obtain an audio signal that explains the screen that is being played at variable speed, use an external tape recorder, etc., and record it on V
A system has been considered in which an audio signal for explanation is appropriately obtained in synchronization with the TR. However, such a system inevitably becomes large in size and requires complicated operation.

(Object of the Invention) In view of the above-mentioned drawbacks, the present invention has been developed in such a way that when a video signal is reproduced from a medium on which a video signal and an audio signal are recorded, it is not possible to obtain an appropriate audio signal no matter what reproduction method is used. The purpose is to provide a playback device that can.

(Description of Embodiments) Hereinafter, embodiments in which the present invention is applied to a VTR will be described.

FIG. 1' is a diagram showing a head arrangement of a VTR as an embodiment of the present invention, and FIG. 2 is a diagram showing recording tracks on a magnetic tape by the VTRK shown in FIG. In FIG. 1, a head 12 for erasing the entire width of the magnetic tape 4 is a drum having a rotary head 6.7, 5 is an audio signal erasing head, 5 is an audio signal recording/reproducing head, 10
11 is a vertical boss for guiding the tape), 12.13 is an inclined post for guiding the tape, 14 is a capstan for driving the running of the tape 40, 15 is a pinch roller that is pressed against the capstan 14, and 16 is a vertical boss for controlling the running direction of the tape 4. This is arrow 1 shown.

The rotary head 6.7 sequentially records video signals on diagonal tracks 9 on the tape 4 and reproduces them from the same tracks 9. The head 5 also records an audio signal on a longitudinal track 8 provided at the end of the tape 4, and reproduces it from the same track 8. Further, the head 3 is a head for erasing the same track 8.

FIG. 6 is a diagram showing a circuit configuration of a VTR as an embodiment of the present invention, the head arrangement of which is shown in FIG. 1. First, the operation during recording will be briefly explained.

Reference numeral 20 denotes a video signal input terminal, and the input video signal is converted into a signal form suitable for recording by the video signal recording processing circuit 22, and then is sent to the recording side west terminal of the recording/reproducing switch 24, 26 as described above. is recorded on the magnetic tape by a rotary head 6.7. On the other hand, the audio signal is inputted from the input terminal 54, applied with an AC bias by the audio signal recording processing circuit 36, and supplied to the audio recording/reproducing head 5 via the R terminal of the recording/reproducing changeover switch 38, where it is sent to the audio recording/reproducing head 5 at the end of the tape. recorded on a longitudinal track.

Next, the operation during normal playback will be explained. The video signal reproduced by the head 6゜7 is transferred to the recording/playback switch 24.26.
The signal is supplied to the head switching circuit 28 through the P terminal of , and converted into a continuous signal by the circuit 28 .

Then, the video signal reproduction processing circuit 30 returns the signal to its original form and outputs it from the terminal 32. On the other hand, the audio signal reproduced by the head 5 is transferred to the recording/playback switch 38. The signal is supplied to a waveform shaping circuit 42 via a preamplifier 40, where it is returned to the original signal. This signal is the changeover switch 4
The audio signal is output from the audio output terminal 4B via the A terminal of 4 and the reproduction amplifier 46. The changeover switch 44 is controlled by a system controller 52 according to the mode selected by a mode selector 50 such as an operation switch, and is connected to the A terminal during normal playback.

FIGS. 4(5), (B), and (C) show RAM-A64 when the VTR shown in FIG. 6 is in the variable speed playback mode.
5 is a timing chart showing an example of the state of RAM-B66.

First, the operation during slow motion playback will be explained using the timing chart shown in FIG.

For example, tape speed 1/? The operation when performing a 1/6 throw with the speed set to i will be explained. 1A ef- with mode selector
When you select motion playback, the system controller 5
2 controls the capstan drive circuit 54, and the capstan 56 rotates at a speed of 1A during normal recording and reproduction.

Further, the switch 44 is switched to the B terminal. At this time, an enlarged reproduction slow motion image signal is output from the terminal 62. On the other hand, the waveform shaping circuit 42 obtains an audio signal with a frequency 1/6 of the normal frequency. This audio signal is sampled and held by a sample and hold circuit (SIH) 60. This sampling frequency is 163 if the maximum frequency of the audio signal to be stored is chosen to be 8.192KHz.
84/3 H2 (approximately 5.46 KHz). The sampled and held analog audio signal is passed through an analog-to-digital converter (N) 62 to I'L A M
-At4°Written to RAM-B66 alternately. R
AM-At4. If each RAM-B 66 has a capacity of 256 bits, it will be possible to store a 4-bit digital audio signal of 4 seconds each.

In FIG. 4(5), (a) shows the state of RAM-At4, and (b) shows the state of RAM-B66.

In FIG. 4, the period indicated by write indicates that the write clock is supplied, and the period indicated by read indicates that the read clock is supplied. During the period indicated by tl in the fourth drawing, a 5.46 KHz write pulse is supplied to the RAM-At4, and an audio signal is written. On the other hand, a read pulse of 16.38 KHz is supplied to the RAM-B 66, and the stored audio signal is read out. That is, the period t1 is 4 seconds if the RAM is 64 bytes. Like this KR
The signal read from the AM-At4 or the RAM-B66 is converted into an analog audio signal by the digital-to-analog converter 68, and outputted to the output terminal 48 via the switch 440B terminal and the amplifier 46.

Now, if the system controller 52 causes the period t1 to start immediately after selecting slow motion playback, no audio signal is stored in the RAM-B 66 yet, so no output audio signal can be obtained during this period. . Also, of course, it is not necessary to supply the RAM-B66 with successive clocks.

During the period t2 in FIG. 4(5), the write clock (16,36KI(z)) is supplied to the RAM-At4, and the audio signal is written.

No clock is supplied to RAM-B66. Therefore, no audio signal can be obtained from the terminal 48 during this period (8 seconds). In the period t3, a read clock (5.46 KHz) is supplied to the RAM-At4, and the audio signals stored in the periods t1 and t2 are read out. On the other hand, R.A.
A write clock is supplied to the M-B 66 at t3μ4, and the audio signal is stored. R, A.M.
The audio signal stored in -866 is read out in the next period t5.

That is, an audio signal is obtained from the terminal 48 during periods t1 and tsK, and by sequentially repeating these periods t1 to t4 (24 seconds), a reproduced audio signal can be obtained even during slow motion reproduction.

Figure 4 (B) shows the RAM during slow motion playback.
-A64 is a diagram showing another example of the state of RAM-B66. R, AM-A64 is in the period t in Fig. 4 (c).
1' and t2, and reading is performed during period ti, and the RAM-B 66 performs writing during period tt and t7, and reading during period t2'. and period t11 to t4
By sequentially repeating ', a reproduced audio signal can be obtained from the terminal 48 at t2' and t7.

As shown in FIG. 4(B), when the RAM is operated, a continuous 8 second audio signal is obtained once in one cycle (24 seconds).

Next, an example of the operation of RAM-A64 and RAM-B66 when performing high-speed search playback in a VTR having the configuration shown in FIG. 3 is shown in FIG. 4 (q).
In this case, a write clock (16.58 x 5. = 81.9 KHz in case of 5x speed search) is supplied to RAM-866, and during normal playback (in case of 5x speed search, the audio signal that should be 4 seconds long is stored for 0.8 seconds). .

Similarly, in 2, write to 11 (, AM-A154.RAM-At54, RAM-B
The audio signals from 66 are read by τ2 and τ3, respectively.
．． This is done at τ4 and τ1. Then, steps τ1 to τ4 are sequentially repeated.

That is, when performing such a 5x speed search, continuous audio signals of 8 seconds are output from the terminal 48 one after another.

According to the configuration as described above, it is possible to obtain an audio signal even during variable speed playback. Therefore, it is particularly effective when searching and reproducing scenes that do not change much on the screen at high speed, or when reproducing scenes such as sports in slow motion.

FIG. 5 is a diagram showing a head arrangement of a VTR as another embodiment of the present invention, and FIG. 6 is a diagram showing recording tracks on a magnetic tape by the VTR shown in FIG. Components in FIG. 5 that are similar to those in FIG. 1, and components in FIG. 6 that are similar to those in FIG. 2 are given the same numbers. 100 is a head for reproducing audio signals for methyl, 102 is a head for erasing still audio signals, 104 is a head for recording still audio signals, and 106 is a second audio track on which audio signals for methyl are recorded.

FIG. 7 is a diagram showing a circuit configuration of VTl'L as another embodiment of the present invention whose head arrangement is shown in FIG. 5. 6th
Components similar to those in the figures are given the same numbers.

The usage and operation of this VTR 1 will be explained below with reference to Figures 5.6.7.

This VTR is designed to specify in advance a screen for still playback of recorded video, and to record and play back an audio explanation of that screen.

First, the operation during normal recording and reproduction will be briefly explained.

When performing normal recording, the video signal input from the terminal 20 is converted into a signal form suitable for recording by the video signal recording processing circuit 22, and is sent diagonally by the head 6.7 via the R terminals of the switches 24 and 26. Recorded on track 9. -10,000 terminals 64
The input audio signal is sent to the A terminal of the audio signal recording processing circuit '56° switch 108 and the recording amplifier 1.
10. The signal is recorded on the audio track 8 by the head 5 via the switch 1120R terminal. When performing normal playback, the video signal sequentially played back from the diagonal track 9 by the head 6.7 is supplied to the head switching circuit 28 via the P terminal of the switch 24.26, and the video signal is supplied to the head switching circuit 28 through the P terminal of the switch 24.
After the signal is made into a continuous signal at the video signal reproduction processing circuit 60, it is returned to the original signal form and then output from the output terminal 32. On the other hand, the audio signal reproduced by the head 5 is supplied to the audio signal reproduction processing circuit 168 via the P terminal of the switch 112 and the reproduction preamplifier 166, and is further supplied to the output terminal 4B via the A terminal of the switch 140 and the reproduction amplifier 46. Output. The switches 24, 26, and 112 are recording/reproducing changeover switches, and are connected to the R terminal during recording and to the P terminal during playback. It is also assumed that the switches i08 and 140 are connected to the A terminal by the system controller 52 during normal recording and reproduction.

Next, the operation when recording an explanatory audio signal for a designated screen onto the second audio track 106 will be described. During normal playback, the user looks for a screen on which he/she wants to record explanatory audio while looking at the monitor screen, and when that screen appears, the mode selector 50 is used to switch to still playback mode. Head 5 and head 100 are currently playing a still screen recorded on track 9a of diagonal track group 9.
．． The position of the head 104 is as shown in FIG. In this state, when the mode selector 5o is used to specify the recording mode of the explanatory audio signal, the tape 4 is moved to the arrow 1.
6, an audio signal of a predetermined length T is recorded in the diagonally shaded portion of the track 106 in FIG.

The operation of the seventh answering section at this time will be explained.

When the recording mode of the explanatory audio signal is specified using the mode selector 5o in the still playback state, the timer 144 is set by the action of the system controller 52, and the capstan drive circuit 54 operates the capstan 56 at the same speed as during normal recording and playback. let Furthermore, at the same time, the connection of the switch 108 is changed to the B terminal, and the gate circuit 1 is connected.
Turn on 20.

Here, the user starts inputting an audio signal for explanation from the terminal 64. The input audio signal is processed (for example, by adding an AC bias) in the audio signal recording processing circuit 66 in the same manner as during normal recording, and is supplied to the mixer 116 via the B terminal of the terminal 10B. Immediately after the recording mode of the explanatory audio signal is set, the mixer 116 mixes the large amplitude pulsed synchronization signal obtained from the synchronization forming circuit 114 and the explanatory audio signal to obtain a mixed signal.

The mixed signal begins to be recorded by the head 104 via the recording amplifier 11B and the gate circuit 120 on the shaded area of the track 106 shown in FIG. The aforementioned large-amplitude pulse-like synchronization signal is recorded in the portion shown in FIG. 6 106a.

When the timer 144 measures a predetermined time T, the system controller 52 connects the switch 10B to the A terminal;
Then, the gate 120 is turned off. Immediately before that, a pulsed synchronization signal is generated from the synchronization signal forming circuit 114.

This pulsed synchronization signal will be recorded in the portion shown in FIG. 6 106b, but it is preferable to make it distinguishable from the synchronization signal recorded in the portion shown in 106a described above.

For example, one large-amplitude pulse may be inserted into the portion indicated by 106EL, and two pulses may be inserted into the portion indicated by 106b.

When the switch 10B is connected to the A terminal and the gate 120 is turned off, recording of the explanatory audio signal is stopped. Also, at this time, the distance between the head 100 and the head 104 is j
When the running speed of 1 tape 4 is v1 recording time T, νT
-1, and track 106 on tape 4
An explanatory audio signal is recorded over a length l. However, since T is determined by the capacity of the RAM 132, which will be described later, and υ is also determined by the tape running speed during normal recording and reproduction, the inter-head spacing l must be determined as appropriate.

Next, the operation in the reproduction mode of the explanatory audio signal will be explained. The head 5 traces the track 8 shown in the sixth figure, and the head 100 traces the track 106 shown in the sixth figure. Further, during normal reproduction, the reproduction output of the head 5 is obtained from the output terminal of the terminal 46. When the synchronization pulse recorded in the above-mentioned 106a is reproduced by the head 100 in the explanatory audio signal reproduction mode, the synchronization pulse is transmitted to the reproduction preamplifier 122. The signal is supplied to the system controller 52 via the synchronization separation circuit 124, and the system controller 52 drives the clock 142 in response. However, it is assumed that the entire device is kept in the normal playback mode. As mentioned above, the audio signal recorded in the shaded area of the track 106 is supplied to the waveform shaping circuit via the sync separation circuit 124, where the AC bias is removed, the sample is bolded at 8/I (/2B), and the audio signal is /
D as a digital signal, and during time 1 RAN+
132. Here, the capacity of RAM132 is 2
If the audio signal is set to 56 bits, the audio signal is converted to 4 bits, and the sampling frequency is 8.192 KHz, the period T will be 4 seconds.

Now, when the reading into the RAM 152 is completed in period T, the tape transport speed during recording of the explanatory audio signal is equal to the tape transport speed during normal playback, so 106b
The synchronization pulse recorded in the head 100 will be reproduced.

FIG. 6 shows the position of each head at this time.

The synchronization pulse written in 106b is the synchronization separation circuit 1.
When the signal is supplied from 24 to the system controller 52, the capstan drive circuit 54 stops the capstan 56 and enters the still playback mode, that is, the designated screen is played back as a still and outputted from the terminal 52. Also, at this time, the switch 140 is connected to the B terminal, and the RAM1
32 is in read mode, and the aforementioned four seconds of explanatory audio signal is sent to D/A 134. It is output via the B terminal of the switch 140 and the reproducing amplifier 46. and RAM
When the reading from 132 is completed, the normal playback mode is again set.

By configuring as described above, a pre-designated screen can be reproduced as a still image and an audio signal for explaining it can be obtained.

(Description of Effects) As explained above using the embodiments, according to the playback device of the present invention, a suitable audio signal can always be obtained regardless of the playback mode. In this case, a reproduced audio signal can be obtained during any variable speed reproduction.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the head arrangement of a VTR as an embodiment of the present invention, FIG. 2 is a diagram showing recording tracks on a magnetic tape by the VTR shown in FIG. 1, and FIG. 6 is similar to FIG. 1. A diagram showing the circuit configuration of a VTR showing the head arrangement.
Each R when in the variable speed playback mode
A timing chart showing an example of an AM state, FIG. 5 is a diagram showing a head arrangement of a VTR as another embodiment of the present invention, and FIG. 6 shows recording tracks on a magnetic tape by the VTR shown in FIG. 7 is a diagram showing the circuit configuration of a VTR whose head arrangement is shown in FIG. 5. 4 is a magnetic tape as a recording medium, 5 is an audio recording/reproducing head, 6.7 is a rotating video head, 8 is an audio track, 9 is a video track, 50 is a mode selector as an operating means, 52 is a system controller, 58
100 is an explanatory audio signal playback head, 1o4 is an explanatory audio signal recording head, 1o6 is a second audio track, 132 is a RAM, 142 is a clock generation circuit, 14
4 is a timer. Applicant Canon Co., Ltd.

Claims (1)

[Claims] 1) A device for reproducing a video signal and an audio signal recorded on the same recording medium, comprising a first reproducing means for reproducing the video signal on the medium, and a first reproducing means for reproducing the audio signal on the medium. a second reproduction means, a storage means for storing audio signals of a predetermined period of time, an operation means for controlling the first reproduction means to obtain a desired reproduction video signal, and a storage means for controlling the first reproduction means to obtain a desired reproduction video signal; and means for switching between the output of the second reproducing means and the output of the second reproducing means.