JPS601657A - Data recording and reproducing device - Google Patents

Abstract

PURPOSE:To widen a main track width and to improve the sound quality and to facilitate an easy production of a fixed head, by recording and reproducing the 1st auxiliary data for high-speed reproduction and the 2nd auxiliary data for fixed-speed reproduction to an from a piece of auxiliary track. CONSTITUTION:The 1st auxiliary signal S-AMS which must be reproduced in a high-speed reproduction mode is supplied to a signal converting circuit 30 via a terminal. While the 2nd auxiliary signal S-SUB which must be reproduced only in a fixed-speed reproduction mode is supplied to the circuit 30 via a terminal 8. The bit frequency of the signal S-AMS uses a large wavelength; while the bit frequency of the signal S-SUB uses a small wavelength. At the circuit 30, the signal S-SUB is inverted in phase and the signal S-SUB is synthesized in a DC shift mode when the signal S-AMS shows the minus information. In a reproduction system, the signal S-AMS is extracted and separated from the DC shift component of the signal S-SUB through a signal converting circuit 50.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is a device in which an audio signal (main signal) such as a voice signal is digitized and recorded and reproduced by a fixed head. The present invention relates to a data recording/reproducing device that records data (data such as the beginning of a song, address, etc.) on a track different from a main signal recording track.

BACKGROUND TECHNOLOGY AND PROBLEMS For example, when an audio signal such as a voice signal is digitally coded (for example, converted to PCM) and recorded on a magnetic tape in a compact cassette using a fixed head, a multi-channel fixed head is used as the fixed head. A data recording and reproducing device (digital audio tape recorder (DAT)) has been proposed that simultaneously records on a plurality of data tracks T1 to Tn (for example, n = 20) and reproduces a predetermined audio signal therefrom. .

An example of this DAT tape format is shown in Figure 1. The figure shows the tape format for round-trip playback (4'11 tapes on both sides), and the trunk for data recording is 20 tapes on each side. As a fixed head for data recording and reproduction, a magnetic flux responsive thin film head with a multi-channel configuration is used.

In addition to trunk 1 for recording main data, it also plays recorded audio signals (music No. 4g), addresses,
A track Ta for recording auxiliary data that records auxiliary data related to the music signal, such as song time.

'1'b is the installation number J.

Does auxiliary data need to be played back reliably even if the tape is running at a different speed than the data recording speed, for example, 30 times the constant speed? I! There are auxiliary data data S and auxiliary data SUB that is necessary only during constant speed reproduction. For example, the auxiliary data AMS "ζ" is data for determining the presence or absence of a song, and the auxiliary data SUB includes the number from the beginning of the tape of the song, the time from the beginning of the tape, the time within the song, This data indicates the song index (number of songs, performance name, etc.), emphasis characteristics, copy prohibition, etc.

Also, depending on the case, ζ may include data indicating the beginning of the song in the after-stroke. This is because there are times when it is necessary to play a song even in constant speed driving mode. The following explanation is an example in which song cue data is also included.

In order to record these different types of auxiliary data AMS and SOB, there are in principle two tracks ('I''a) for auxiliary data recording, as shown in FIG.

Tb) If it is not provided, ζ will not be true.

However, since the tape width of an audio cassette tape is very narrow at 3.81 mm, when two auxiliary tracks Ta, ]"b are provided, the number of main trunks Ti for recording main data must be reduced. However, the 1-rank pinch itself must be narrowed.

Reducing the number of main tracks Tf is undesirable from the viewpoint of sound quality, and narrowing the track pitch causes difficulties in manufacturing the fixed head. Taking these points into account, it is better to use only one auxiliary track as shown in Figure 2 for the auxiliary track C1, and not reduce the number of main trunks Ti with the specified trunk visona by that amount, in terms of sound quality and manufacturing of the fixed head. preferred from the viewpoint of

In general, when two auxiliary trunks are used, the number of channels for the recording system, the reproduction system, and the fixed head for recording and reproduction increases accordingly, which increases the circuit regulations and the like, which becomes a factor in cost increase.

OBJECTS OF THE INVENTION Accordingly, in this invention, one auxiliary track includes first auxiliary data D-AMS, which is required only during commercial reproduction, and second auxiliary data D-5OB, which is required only during constant-speed reproduction. In addition to being able to record any of the following data, it is also possible to reliably reproduce each data according to the tape speed.

Pillar of the Invention (Important) Therefore, in this invention, the first
auxiliary data D-AMS and second auxiliary data D-S
U and B are combined and recorded. The bit frequency of the first auxiliary data l)-AMS uses a long wavelength, whereas the bit frequency of the second auxiliary data D-3IIB uses a short wavelength. Then, during data synthesis, when the first auxiliary data D-AMS indicates - information, the second auxiliary data low Sun is synthesized in a phase-inverted and DC-shifted state.

During data reproduction, the first auxiliary data D-5OB is extracted and separated from the DC shift component of the second auxiliary data D-5OB.

Embodiment Next, a case in which an example of the present invention is applied to DAT will be described in detail with reference to FIG. 3 and subsequent figures.

Figure 3 shows an example of D A T QOI.
0^) is the recording system, and (IOB) is the regenerating thread.

This is a case where a stereo audio signal is used as the audio signal, and the left and right audio signals S, S, supplied to the terminals (IR) and (IL) are converted to an A-'D converter (2
) is converted into a 'C digital code signal, then supplied to an encoder (3) for °ζ encoding processing, and then supplied to a digital modulator (4) for digital modulation. For digital modulation, a phase shift 11J (Biφ-L) method or the like may be used.

The digitally modulated main digital code signal is distributed from the first channel to the 20th channel in this example, and then sent to the corresponding recording amplifiers (481) to (4^20).
) for both recording and playback heads HM1~■1 concave? 0 and simultaneously recorded on the corresponding main tracks T1 to T20. (5) indicates a recording tape.

On the other hand, the first auxiliary signal S-8MS, which needs to be reproduced in the 1rli speed reproduction mode, is transmitted through the terminal (7), and the second auxiliary signal, which needs to be reproduced only in the constant speed reproduction mode, is transmitted through the terminal (7). S-5UB is connected to the signal conversion circuit (3) through the terminal (8).
0). In this signal conversion circuit (30), as will be described later, first and second auxiliary signals S-^ are pasted.

S-3Ut1 is converted into a predetermined digital code signal, subjected to predetermined signal processing, and then synthesized and output. This composite data AD is supplied to the °ζ head Hs via the recording amplifier (14) and sent to the auxiliary trunk l'a.
is recorded in relation to the main digital code signal.

In the inner 4-way system (ITIB), the signal operation (1) is the opposite of that in the recording system (10/l), so a detailed explanation thereof will be omitted.

(1581) to (15820) and (I6) are again I0,
(17) is a digital demodulator, (19) is a decoder, (21) is a D/A converter, and the terminal (2) is a digital demodulator.
2R) (22L), analog audio signals sR and SL are obtained. Also, (50) is the reverse transformation 1 of the composite call 1'AD
/8, and the first auxiliary signal S is connected to the terminal (51A).
-AMS, terminal (51B) D is the second auxiliary (No. d S
-5U11 I got it.

FIG. 4 shows an example of the signal conversion circuit (30), in which the first auxiliary signal S-AMS is I'Ii! First auxiliary data (digital code signal) low eight MS via I child (7)
generator (31). First auxiliary data D-
AMS has a constant tape speed (・i, 76cm/
sec), the recording density is about 3KBPS.
K fly, ) is selected, and if the court is within one song, for example, the court' of l' 1010104 is repeatedly output. Between songs, the code 'ζ, for example, l' 110011004, is repeatedly output at twice the frequency mentioned above.

On the other hand, the second auxiliary input number S-3U8 transmits the second auxiliary data I)-5UB of ζ, for example, 4 bits, through the terminal (8).
(j) is supplied to the generator (32) of (j).

The second auxiliary data D-5II8 is in constant speed driving mode,
For example, the bit frequency is selected to provide a recording density of eoKcps or more.

The second auxiliary data I)-3tlB is further supplied to the second L-mode converter (33) and is converted into bit data such that the 4-bit data becomes DC-free, in this example 8-bit data. , in this example, Fig. 6 A, B
4 upon inversion of the first auxiliary data D-AMS as neo
For the first and last data of the month, code conversion data that always has an "l" character is used. FIG. 6B shows an example of the second auxiliary data 111-3tlB after code conversion.

The code-converted second auxiliary data D-3IJIE and first auxiliary data D-AMS are supplied to a multiplier (34) to perform one-count processing on the digital code signal.

As a result of the calculation process, the first auxiliary data D-AMS
Only when is in the - state, that is, in the inverted state of "0", the composite data AD resulting from the W operation is as shown in Figure 6C.
In this way, the contents of the second auxiliary data row 5IJBH are obtained in an inverted state and DC-shifted to the negative side. Therefore, the synthetic data 80 has three levels.

This is only an example, since the neodata waveform in FIG. 6C can be formed without using the 1 multiplier (34).

This composite data AD is recorded on tape (5).

In addition, (37) is frame sync I? -3YNC generator, frame sync F-3YNC is inserted every block (8x98 bits) of the second auxiliary data row 5tlB. This frame sync F-3YNC is also converted into two IDs.

FIG. 5 is an example of a signal inverse conversion circuit (50).

The synthesized data AL reproduced from the head Hs is supplied to the first inverse transformation system (5 (IA)) and the second inverse transformation system (5011) via the reproduction unit (16). The first inverse conversion system (50A) is for reproducing the first auxiliary data (IT No. S-AMS). If data has been inserted, the first inverse conversion system (508) outputs the auxiliary signal qS in the steady running mode.
There is no particular need to reproduce Ms to -.

Therefore, in the following, the regeneration operation in the commercial transport mode will be explained.

In the crystal sluggish running mode in which the vehicle travels at N times the constant speed (N is about 1 to 30), the cut-off frequency of the low-pass filter (52) is equal to N of the bit frequency of the first auxiliary dehetaro 8 MS.
controlled more than twice as much. This control is performed based on data i'c which detects the tape speed.

This is because the tape speed can be set to an arbitrary speed between constant speed and N times speed, and the bit frequency to be extracted changes depending on the tape speed.

Therefore, at any tape speed, the envelope output of the composite data AD is obtained from the low pass filter (52). The composite data AD is in the form of the auxiliary data D-5tlBM modulated by the first auxiliary data MS, as shown in FIG. The envelope output of the first auxiliary de-taro-chou IS, which is a variable two-cycle signal, is obtained.

The output of the low-pass filter (52) is supplied to a waveform shaping circuit (53) having three levels and outputs ζ“1”.

The data detector (55
). Therefore, digital PLL (56
) is provided, and a clock CK synchronized with human power is supplied to the data detector (55). The output is sent to the decoder (5
8) to regenerate the MS back to the original first auxiliary signal S-.

This first auxiliary signal S-AMS ly< CPU (
(not shown), its contents are displayed, and the tape transport system is controlled.

On the other hand, the second inverse conversion circuit (50B) is for generating 114 second auxiliary data D-3IJBM during constant speed driving mode, and the composite data AD is directly supplied to the equalizer amplifier (62). As a result, code amount interference is removed. The waveform of the digital code signal of the second auxiliary data D-5UBM output from the equalizer amplifier (62) is shaped by the waveform shaping circuit (63) configured in the same manner as described above, and the output is selectively shaped. It is supplied to the inverter (64).

This selectivity inverter (64) is not shown in FIG. 5C and is for returning the DC-shifted digital code signal to its original state. can do. Since this inverter (64) is selective, in the case of a digital code signal of "1", it is output as is.

The output of the inverter (64) is supplied to a data detector (65) and a digital PLL (66). The output is a code converter (67), which outputs 4 8-bit digital code signals.
The second auxiliary data D-3UB, which is inversely converted to the focus digital code signal and output from this, is sent to the decoder (68
) is supplied to the original second auxiliary signal -3-S U 11
is born.

The reproduced second auxiliary signal S-3OB is also supplied to the CPU, and the corresponding contents (song address, previous playing time, emphasis characteristics, etc.) are displayed, and the tape transport corresponding to the contents is displayed. system is controlled.

In addition, in the constant speed driving mode, the first auxiliary signal S-AMS
is not reproduced, but since the data for starting the song is included in the second auxiliary data D-3UB, the beginning of the song can be found even in the constant speed driving mode.

When making the bit frequency of the second auxiliary data D-5OB higher than the double value (60KBPS),
The first auxiliary data D-AMS can be reproduced even if the digital code signals at the beginning and end of the second auxiliary data D-3OB shown in FIG. 6C do not necessarily correspond to "1".

As described in detail, in the present invention, the first auxiliary data D-AM that must be reproduced in the high-speed driving mode
S and the number that needs to be regenerated only in constant speed driving mode? The auxiliary data 1)-5OB are frequency-multiplexed and recorded on one auxiliary track T''a, and desired auxiliary data can be extracted and separated from this, so the following features are achieved. have

First, since the number of main tracks Ti is not reduced, the sound quality is excellent.The trunk width of the main track 1i can also be made wider due to the absence of the auxiliary track Tb.This makes it easier to manufacture the fixed head. Since the recording system and internal thread can also reduce the circuit scale, the advantages mentioned above are compatible with D A T QO.
) can reduce costs.

If technology advances and it becomes possible to easily manufacture a multi-gap fixed head that supports the number of tracks shown in Figure 1, it will be possible to record other information on the auxiliary l-rack Tb, making it possible to Increases, etc. can be easily achieved.

The second auxiliary data D-5IIB is the first auxiliary data D-
Since the digital code signal of AMS is inverted only when it is in the negative state, and the DC shift is performed, the first and second auxiliary data D-AMS, D- are converted from the composite data AD. 8UB can be reliably extracted and separated.

[Brief explanation of drawings]

9AI and 2 are explanatory diagrams of tape patterns, FIG. 3 is a block diagram of an example of a data recording/reproducing device provided for this invention, FIG. 4 is a block diagram showing an example of an auxiliary data signal conversion circuit, and 514JI is a block diagram showing an example of the signal inverse conversion circuit, and FIG. 6 is a block diagram showing an example of the signal inverse conversion circuit. It is a diagram used to explain the work of IJ. (30) is a signal conversion circuit, (50) is a signal inverse conversion circuit,
D-A and D-5UB are first and second auxiliary data.

Claims (1)

[Claims] First digital code data converted at a first bit rate and second digital code data converted at a second bit rate shorter than the first bit rate are combined, and Only when the first digital data is in a negative state, the second digital data is DC-shifted and synthesized with the first digital data, and this synthesized digital data is placed on a track separate from the main signal recording track. A data recording and reproducing device in which necessary digital code data is extracted and separated from first and second digital code data recorded on an auxiliary track and reproduced from the auxiliary trunk.