JPH0610483Y2 - Digital audio signal playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a digital audio signal reproducing apparatus suitable for use in a tape recorder for reproducing an audio signal from a magnetic tape recorded as a digital signal.

[Outline of device]

According to the present invention, a plurality of magnetic heads for reproducing a digital audio signal recorded on a magnetic tape are arranged on a rotating drum at equal intervals at a predetermined angle, and the plurality of magnetic heads intermittently output the digital audio signal. In a digital audio signal reproducing device having a tape recorder adapted to reproduce, a signal processing device for processing a reproduced digital audio signal from the tape recorder, and a transmission line connecting the tape recorder and the signal processing device,
Connection between the tape recorder and the signal processing device by transmitting the control signal of the tape recorder and the signal processing device through the transmission line when none of the plurality of magnetic heads is reproducing the digital audio signal. However, only a digital audio signal transmission line is required, and a dedicated transmission line for supplying a control signal is not required.

[Conventional technology]

Previously, there has been proposed a video tape recorder which records an audio signal as a digital signal together with a video signal for reproduction.

FIG. 4 is a diagram showing an example of a rotary head drum of this type of video tape recorder. This rotary head drum is
The upper drum (1) is rotatably supported around a center O, and the first to twelfth magnetic heads (2) to (1
3) are installed at regular intervals of 30 °. The functions of the respective magnetic heads are as follows: the first magnetic head (2) is the erasing head of the video signal track, the second magnetic head (3) is the recording / reproducing head of the video signal track, and the third, fourth and third magnetic heads. 5
The magnetic heads (4), (5), and (6) are playback heads for confirming the recording of the digital audio signal track (hereinafter referred to as "conch heads"). The sixth magnetic head (7) is a special reproduction head of the video signal track, and the seventh, eighth and ninth magnetic heads (8), (9) and (10) are the reproduction head and the tenth of the audio signal track, respectively. , 11th and 12th magnetic heads (11),
(12) and (13) are the recording heads of the audio signal track, respectively. Since the magnetic heads (2) to (13) are attached to the upper drum (1) in this manner, recording is performed on the magnetic tape (14) with a format as shown in FIG. 5, for example. That is, a video track (15) that is inclined with respect to the longitudinal direction (travel direction) is formed in the central portion of the magnetic tape (14), and three video tracks (15) are provided below the video track (15). Book first, second and third digital audio tracks (16a), (16b) and (16c) are formed. The video track (15) is recorded / reproduced by the second magnetic head (3) and is reproduced by the sixth magnetic head (7) only during special reproduction. The first, second and third digital audio tracks (16
In a), (16b) and (16c), these three recordings are made for one video track (15), and the tenth, eleventh and twelfth magnetic heads (11), (12) and (13) are recorded. ) Records the first, second and third tracks (16a), (16b) and (16c) respectively, and the third, fourth and fifth magnetic heads (4), (5) and (6) respectively. Or the seventh,
The 8th and 9th magnetic heads (8), (9) and (10) respectively provide the 1st, 2nd and 3rd tracks (16a), (16b) and (16c).
Is reproduced, and these three tracks (16a), (16b), (16c)
By this, one unit of digital audio signal is obtained. A fixed head (not shown) is placed on the magnetic tape (14).
The first analog audio track (17) above the video track (15) as a track for recording / playback by
And the second analog audio track (18) is connected to the video track (15) and each digital audio track (16a), (16).
A control track (19) is formed between b) and (16c), and a third analog audio track (20) is formed below each of the digital audio tracks (16a), (16b), and (16c).

Here, the congestion heads (4), (5), and (6) and the regeneration heads
The reproduction of the digital audio signal by (8), (9) and (10) is performed by the corresponding video signal track (15) in each field.
Playback and immediately after playback from the conch head (4) to the replay head (10)
Are played back in order.

That is, assuming that the three digital audio tracks (16a), (16b) and (16c) corresponding to one video track (15) are A track, B track and C track, respectively, as shown in FIG. 3A. , First by the first concealed head (4) A
Signal of the track is regenerated, then the second concatenation
The signal of the B track is reproduced by (5), and then the signal of the C track is reproduced by the third conjugate (6). And each of these conghed heads (4), (5) and (6)
Immediately after reproduction by, the first digital audio signal reproduction head (8) reproduces the A track signal, and then the second digital audio signal reproduction head (9) reproduces the B track signal. Finally, the C track signal is reproduced by the third digital audio signal reproducing head (10). In addition, each of the concealed heads (4), (5),
(6) and the respective digital audio signal reproduction heads (8),
The reproduced signals by (9) and (10) are obtained within the range of 10 ° at equal intervals of 30 ° at the rotation angle of the upper drum (1), respectively.

On the other hand, the digital audio signal recording head (11),
Digital audio signal or digital audio signal reproduction head recorded by (12) and (13) (8), (9) and (1)
The digital audio signal reproduced by (0) and the conjugates (4), (5) and (6) is exchanged with the analog audio signal by the digital audio processor. Sixth
The figure shows this type of configuration.In the figure, (21) is a video tape recorder, and a digital audio processor (22) is provided separately from this video tape recorder (21). The (21) side controls a signal processing device having a function as a digital audio processor (22), and a video day pre-recorder is provided between the video tape recorder (21) and the digital audio processor (22).
Playback digital audio signal supply line (23) from (21), recording digital audio signal supply line (24) from digital audio processor (22), and video tape recorder (21)
There are three control signal supply lines (25) for the digital audio processor (22) from the above. Then, at the time of recording, a control signal for instructing recording or the like is supplied from the video tape recorder (21) to the digital audio processor (22) via the control signal supply line (25) and is obtained at the audio signal input terminal (22a). The analog audio signal is converted by this digital audio processor (22) into a digital audio signal in the format instructed by the control signal, and this digital audio signal is transferred to the video tape recorder (21) via the recording digital audio signal supply line (24). It is supplied and the video tape recorder (21) records on the magnetic tape by the heads (11), (12) and (13). Also, during playback, a control signal for instructing playback etc. from the video tape recorder (21) via the control signal supply line (25) is sent to the digital audio processor (22).
The digital audio signal supplied to the digital audio processor (22) via the digital audio signal supply line (23) which is reproduced from the magnetic tape by the video tape recorder (21) and is reproduced by the control signal. Is converted into an analog audio signal, and this analog audio signal is supplied to the audio signal output terminal (22b). With such a configuration, recording / reproducing of audio signals is performed.

[Problems to be solved by the invention]

By the way, as mentioned above, the digital audio processor
If the (22) is separate from the videotape recorder (21), for example, install the videotape recorder (21) at the place to operate, and install the digital audio processor (22) at the sound source or playback location. Installed near a video tape recorder (2
The three signal supply lines (23), (24) and (25) between 1) and the digital audio processor (22) may be lengthened considerably. When the signal supply lines (23), (24), and (25) are long in this way, it is inconvenient to handle if the number of lines is large, and an expensive signal line with good performance is taken into consideration in consideration of signal attenuation. It has to be used, and in some cases, a signal amplifier is required for each line, and there is an inconvenience that the connection between the video tape recorder (21) and the digital audio processor (22) is expensive.

In view of the above points, the present invention provides a digital audio signal reproducing device which enables a video tape recorder (21) and a digital audio processor (22) to be connected with a simple structure and at low cost. With the goal.

[Means for solving problems]

The digital audio signal reproducing apparatus of the present invention, for example, as shown in FIG. 1, has a plurality of magnetic heads for reproducing a digital audio signal recorded on a magnetic tape on a rotary drum at regular intervals. A tape recorder (21) arranged to intermittently reproduce a digital audio signal by a plurality of magnetic heads, and a signal processing device (22) for processing a reproduction digital audio signal from the tape recorder (21), In a digital audio signal reproducing device having a transmission line (29) connecting a tape recorder (21) and a signal processing device (22), transmission is performed when none of a plurality of magnetic heads is reproducing a digital audio signal. The control signals of the tape recorder (21) and the signal processing device (22) are supplied via the line (29).

[Action]

The digital audio signal reproducing device of the present invention supplies the control signal through the digital audio signal transmission line (29) when there is no digital audio signal, thereby enabling the tape recorder (21) and the signal processing device (22) to operate. The digital audio signal transmission line (22) is the only connection required.

〔Example〕

Hereinafter, one embodiment of the digital audio signal reproducing apparatus of the present invention will be described with reference to FIGS. This first
In the figure, parts corresponding to those in FIGS. 4 to 6 are designated by the same reference numerals, and detailed description thereof will be omitted.

The digital audio signal reproducing apparatus of this example is the same as the above-mentioned fifth one.
In a video tape recorder for recording with the same format as in the example shown in the figure, the arrangement of the magnetic heads on the rotating head drum is also the same as in the example of FIG. 4, and the magnetic heads are arranged at equal intervals of 30 °. The digital audio reproduction signal from the head is 1 at the rotation angle of the upper drum (1) as shown in FIG. 3A.
Obtained in the range of 0 °.

The recording / reproducing apparatus of this example, as shown in FIG. 1, has a digital audio signal output terminal (26) of a video tape recorder (21).
Is connected to the first fixed contact (28a) of the first switching switch (28), and the control signal output terminal (27) is connected to the first switching switch (28).
To the second fixed contact (28b) of the. The movable contact (28c) of the first switching switch (28) is connected to the video tape recorder (21) side of the digital audio reproduction signal supply line (29), and the digital audio reproduction signal supply line (29) is connected to the digital audio reproduction signal supply line (29). Movable contact of the second switching switch (30) in the digital audio processor (22) with the processor (22) side
Connect to (30c). The first of this second switching switch (30)
The fixed contact (30a) of the digital audio processor (22)
Connect it to the digital audio signal input terminal (31) of the
Connect the fixed contact (30b) of to the control signal input terminal (32).

By connecting in this way, the movable contacts (28c), (30c) of both the first and second switching switches (28), (30) become the first fixed contacts (28a), (30a). When connected to
The playback digital audio signal obtained at the digital audio signal output terminal (26) of the video tape recorder (21) is
It is supplied to the digital audio signal input terminal (31) of the digital audio processor (22), and is converted into an analog audio signal by a control signal described later in this digital audio processor (22). Further, the movable contacts (28c) and (30c) of both the first and second switching switches (28) and (30) are the second contacts.
When it is connected to the fixed contacts (28b), (30b) of the digital audio processor (22), the digital audio processor control signal obtained at the control signal output terminal (27) of the video tape recorder (21) is Is supplied to the control signal input terminal (32) of the digital audio processor (22), and the control signal controls the operation of the digital audio processor (22). Here, for example, the reproduced digital audio signal obtained at the digital audio signal output terminal (26) is a signal as shown in FIG. 3A which is determined by the head arrangement shown in FIG. Further, assuming that the control signal obtained at the control signal output terminal (27) is S, this control signal S is, as shown in FIG. 3B, the first control signal (4) of the digital audio signal in one field. The rotation angle of the drum between the reproduction signal A obtained by the rotation angle of the drum by 10 ° and the reproduction signal B obtained by the second rotation angle of the drum by 10 ° is 20 °. This is a signal obtained while there is no reproduction signal. This control signal S
Is, for example, a wavelength of about 120 KHz, which is lower than that of a digital audio signal. The reproduction signal and the control signal thus obtained are respectively the first and second fixed contacts (28a).
And the switching of the first switching switch (28) supplied to (28b), as shown in FIG. 3, detects the beginning of, for example, one field, and a predetermined period from the detected point until the control signal S is supplied. The movable contact (28c) is moved to the second position only during a predetermined time t ₂ after the time t _{1 has} elapsed until the control signal S is not supplied.
Is connected to the fixed contact (28b) side and the other is connected to the first fixed contact (28a) side. By switching in this way, the signal supplied to the second switching switch (30) on the side of the digital audio processor (22) by the signal supply line (29) reproduces each head as shown in FIG. 3C. A signal and a control signal are put on one line, and a pulse signal as shown in FIG. 2 is obtained. Similarly to the first switching switch (28), the switching of the second switching switch (30) also detects the times t ₁ and t ₂ from the beginning of one field, and the times t ₁ and t ₂ The movable contact (30c) is connected to the second fixed contact (30b) side only during the period, and is connected to the first fixed contact (30a) side during the other period.
By switching in this way, the first fixed contact (30a)
A signal as shown in Fig. 3A is supplied to the side of the second fixed contact (30
Signals as shown in FIG. 3B are respectively obtained on the b) side, a reproduction digital audio signal as shown in FIG. 3A is supplied to the digital audio signal input terminal (31), and a control signal input terminal (32) is supplied. A digital audio processor control signal as shown in FIG. 3B is supplied. In order to facilitate detection of the above-mentioned predetermined times t ₁ and t ₂ for switching the first and second change-over switches (28) and (30), a predetermined position in a reproduction signal of one field is set. It is also possible to add a specific pulse signal to and to switch the first and second changeover switches (28) and (30) according to the time elapsed from the time of supplying the specific pulse signal.

In this way, by adding the control signal once per field to the no-signal portion in the digital audio reproduction signal, there is no need for a dedicated supply line for supplying the control signal, unlike the conventional case.
The video tape recorder (21) and the digital audio processor (22) can be connected only by a digital audio signal supply line, and the number of lines required for the connection can be reduced. This means that the connection work is simplified, the number of signal lines required for connection is reduced, and when a signal amplifier is required for each line, the number of signal amplifiers can be reduced and the cost can be reduced. .

The position where the control signal is applied is not limited to the example shown in FIG. 3 and may be a position where there is no other reproduced digital audio signal. Further, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[Effect of device]

The digital audio signal reproducing device of the present invention supplies the control signal through the digital audio signal transmission line (29) when there is no digital audio signal, thereby enabling the tape recorder (21) and the signal processing device (22) to operate. Since only the digital audio signal transmission line needs to be connected, the connection work is simplified and the number of signal lines required for connection is reduced, and even if a signal amplifier is used, this signal amplifier can be reduced, and at low cost. There are profits that can be constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital audio signal reproducing apparatus of the present invention, FIGS. 2 and 3 are diagrams for explaining the example of FIG. 1, FIG. 4 is a block diagram of a rotary drum, FIG. 5 is a diagram showing an example of a recording format of a magnetic tape,
FIG. 6 is a block diagram showing an example of a conventional digital audio signal reproducing apparatus. Reference numeral (21) is a video tape recorder, (22) is a digital audio processor, (28) is a first selector switch, (29) is a reproduced digital audio signal supply line, and (30) is a second selector switch.

Claims (1)

[Scope of utility model registration request] 1. A plurality of magnetic heads for reproducing a digital audio signal recorded on a magnetic tape are arranged on a rotary drum at equal intervals at predetermined angles, and the digital audio signal is produced by the plurality of magnetic heads. A digital audio signal having a tape recorder adapted to intermittently reproduce data, a signal processing device for processing a reproduced digital audio signal from the tape recorder, and a transmission line connecting the tape recorder and the signal processing device. In the reproducing apparatus, a first changeover switch for switching the reproduced digital audio signal and the control signal to the transmission line on the tape recorder side, and the reproduced digital audio signal transmitted on the transmission line on the signal processing apparatus side. And a second selector switch for switching between the control signal and the control signal. By switching the second changeover switch, the control signals of the tape recorder and the signal processing device are transmitted through the transmission line when none of the magnetic heads reproduces the digital audio signal. A digital audio signal reproducing device characterized in that