JPH0447764Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a recording current adjustment device for a digital signal of a recording/reproducing apparatus that records digital data such as a digital audio signal on a magnetic tape or the like.

[Summary of the idea]

The present invention is a recording current adjustment device for a digital signal of a recording/reproducing device that records digital data such as a digital audio signal on a magnetic tape, etc., and is arranged at least before or after a digital data block, and is arranged at least before or after a digital data block. In a recording current adjustment device for a digital signal of a recording and reproducing device that records and reproduces a preamble signal or a postamble signal as a continuous wave with a wavelength equal to the wavelength along with digital data, the recording current of the digital data and at least the postamble signal or the preamble signal is an adjusting means for adjusting, a detecting means for reproducing the recorded signal and reproducing the postamble signal or preamble signal immediately after recording and detecting the reproduction level, and displaying the amplitude value of the detected reproduction level. The recording current can be adjusted easily and accurately by adjusting the recording current by the recording current adjusting means so that the meter indicates the maximum value.

[Conventional technology]

2. Description of the Related Art Conventionally, as a recording/reproducing apparatus for recording digital data such as a digital audio signal on a magnetic tape, there is, for example, a rotary head type recording/reproducing apparatus. In this rotary head system, digital data recording tracks are provided at an angle with respect to the running direction of the magnetic tape for recording. FIG. 2 is a diagram showing an example of the recording format of this type of recording and reproducing apparatus. In this example, the audio signal of a video tape recorder is digitized. ) a tilted video track 2 is formed and sequentially recorded by a rotating head;
A digital audio track 3 is formed below the video track 2 and is sequentially recorded by a rotating head. A first analog audio track 4 and a second analog audio track 4 are placed above the video track 2 as tracks for recording and reproducing using a fixed head.
An analog audio track 5 is formed, a control track 6 is formed between the video track 2 and the digital audio track 3, and a third analog audio track 7 is formed below the digital audio track 3.

Among the tracks formed in this way, each one of the digital audio tracks 3, that is, the recording format of one field is, for example, the third recording format.
It is configured as shown in the figure. This recording format records the preamble signal 3a in order from the beginning.
280 bits, 8 bits for synchronization signal 3b, 8 bits for block address signal 3c, CRCC (cyclic code)
The signal 3d is composed of 8 bits and the data signal 3e is composed of 256 bits. After that, the synchronization signal 3b, block address signal 3c, CRCC signal 3d and data signal 3e are repeated, and the data signal 3e is composed of 88 bits from 0 to 87.
Consists of times. After the last data signal 3e, a synchronization signal 3b is composed of 8 bits, and finally a postamble signal 3f is composed of 272 bits.

Here, as shown in FIG. 4, the above-mentioned preamble signal 3a and postamble signal 3f are composed of continuously repeated waveforms of the shortest wavelength of the data signal 3e to be recorded, for example, 16 MHz (32 Mbits) continuous repeated waveforms. , this preamble signal 3
By having the signal a and the postamble signal 3f at the beginning and end of one field, there is an advantage that the connection between each field is improved.
Note that the shortest wavelength of the digital data signal 3e is determined depending on the recording method.

[Problem that the invention attempts to solve]

By the way, when recording digital data as described above, there is a risk that good signal reproduction will not be possible unless the recording current is adjusted so that the reproduction level at the time of reproduction is maximized. Therefore, it is required to properly adjust the recording current.

In view of the above, an object of the present invention is to provide a digital signal recording current adjustment device that can easily and effectively adjust the recording current.

[Means for solving problems]

The digital signal recording current adjustment device of the present invention has the following features:
For example, as shown in FIG. 1, it is arranged at least before or after the block of digital data 3e,
In a recording current adjustment device for a digital signal of a recording and reproducing apparatus that records and reproduces a preamble signal 3a or a postamble signal 3f as a continuous wave having a wavelength equal to the shortest wavelength of the digital data 3e together with the digital data 3e, A recording current adjusting means 9 for adjusting the recording current of the amble signal 3f or the preamble signal 3a, and a recording current adjusting means 9 for reproducing the recorded signal and the postamble signal 3f or the preamble signal 3.
detection means 13, 14, 15, 16, and 17 for reproducing the data a immediately after recording and detecting the reproduction level;
The apparatus has a meter 18 that displays the amplitude value of the detected reproduction level, and the recording current is adjusted by the recording current adjusting means 9 so that the display of the meter 18 is maximized.

[Effect]

The digital data recording and reproducing device of the present invention has a preamble signal 3a or a postamble signal 3f.
By reproducing immediately after recording, detecting the amplitude of the reproduction level, and adjusting the recording current of the data signal 3e and at least the preamble signal 3a or the postamble signal 3f according to the amplitude of the reproduction level, a good signal can be easily obtained. Recording current can be adjusted.

〔Example〕

Hereinafter, an embodiment of the digital signal recording current adjusting device of the present invention will be described with reference to FIG.

In FIG. 1, reference numeral 8 indicates a digital audio signal input terminal, and the digital audio signal obtained at the digital audio signal input terminal 8 is supplied to the recording current adjusting means 9.
The digital audio signal whose recording current has been adjusted is supplied via the recording circuit system 10 to a digital audio signal recording head 11 disposed on a rotating drum (not shown), and the digital audio signal recording head 11 records the digital audio signal. is recorded on the magnetic tape 12. Here, the recording current is adjusted by the recording current adjusting means 9 according to an instruction from a meter 18, which will be described later. That is,
In addition to the recording head 11, the rotary drum is provided with a so-called condenser head 13 which reproduces data immediately after recording by the recording head 11 (for example, after several milliseconds).
An amplifier 14, an RF equalizer 15, an RF envelope detector 16, a sample and hold circuit 17, and a meter 18 are connected in this order from the output terminal of the coherent head 13. With this connection, the digital signal recorded by the recording head 11 is immediately reproduced by the recording head 13, and after this reproduced signal is amplified by the amplifier 14, the characteristics of the reproduced signal are adjusted by the RF equalizer 15, and the RF The envelope detector 16 performs envelope detection, the sample and hold circuit 17 samples and holds the envelope-detected postamble signal 3f, and the meter 18 displays the amplitude of the reproduction level of the postamble signal 3f.

By configuring the recording current adjustment circuit in this way, when adjusting the recording current, the meter 18
If the recording current is adjusted by the recording current adjusting means 9 so that the amplitude becomes the maximum, a good recording current will be obtained. That is, the amplitude of the meter 18 becomes maximum because the amplitude of the postamble signal 3f is maximum, and since the postamble signal 3f has the shortest wavelength of the data signal 3e, the amplitude at the shortest wavelength of the data 3e also becomes maximum. , the recording current is such that good reproduction is possible.

It should be noted that even if the signal sampled and held by the sample and hold circuit 17 is the preamble signal 3a, it works in the same way, and the recording current can be adjusted favorably. Further, the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations may be adopted without departing from the gist of the present invention.

[Effect of idea]

As described above, according to the digital signal recording current adjustment device of the present invention, the preamble signal 3a or the postamble signal 3f is reproduced immediately after recording,
The amplitude of the reproduction level is detected, and the data signal 3e and at least the preamble signal 3a or the postamble signal 3f are detected according to the amplitude of the reproduction level.
By adjusting the recording current of , there is an advantage that the recording current can be adjusted easily and favorably.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the digital signal recording current adjustment device of the present invention, FIG. 2 is a diagram showing an overview of an example of a magnetic tape recording format, and FIGS. 3 and 4 2A and 2B are diagrams for explaining digital data recording and reproducing devices, respectively. 3a is a preamble signal, 3e is a data signal,
3f is a postamble signal, 9 is a recording current adjustment means, 13 is a coherent head, 14 is an amplifier, and 15 is a
RF equalizer, 16 is RF envelope detector,
17 is a sample hold circuit, and 18 is a meter.

Claims (1)

[Scope of utility model registration request] Recording of a digital signal by a recording/reproducing device which is arranged at least before or after a digital data block and records and reproduces a preamble signal or a postamble signal as a continuous wave having a wavelength equal to the shortest wavelength of the digital data together with the digital data. The current adjustment device includes a recording current adjustment means for adjusting the recording current of the digital data and at least the postamble signal or the preamble signal, and reproducing the recorded signal and reproducing the postamble signal or the preamble signal immediately after recording. and a meter for displaying the amplitude value of the detected reproduction level, and the recording current adjusting means adjusts the recording current so that the meter displays the maximum value. A recording current adjustment device for digital signals, characterized in that: