JPH02282955A - Dat device - Google Patents

Abstract

PURPOSE:To perform recording only by designating a sampling frequency by designating the sampling frequency of an audio signal to be digital-recorded on a magnetic tape, setting a device at a recording standby state, and recording only music by identifying the sampling frequency of an input audio signal. CONSTITUTION:A desired sampling frequency is designated by a switch 17a, and also, a DAT device is set at the recording standby state i.e. a recording pause state by using a rec key 17b and a pause key 17c. Also, by setting the switch 17a at an off position, the recording of input data can be performed in spite of the sampling frequency in recording. Hereafter, a system controller 15 judges whether or not a PLL is set at a locked state based on a signal from a digital I/O interface 11, and judges whether or not the sampling frequency of an input signal is the frequency designated by the switch 17a when it is set at the locked state. When coincidence is obtained, the recording is started by controlling the feed of a tape.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a DAT device, and in particular to a DA device that records only digital audio signals at a specified sampling frequency.
Regarding the T device.

<Prior art> By connecting a digital audio device to its digital input terminal, a DAT device records the digital signal input from the digital audio device as a digital signal without passing it through an AD/DA conversion system. I can do it.

Such digital recording enables high-quality recording without any signal deterioration.

Examples of digital audio sources for digital recording include satellite broadcast tuners (BS tuners), CD players, and externally connected DAT devices.

Of these, the sampling frequency of the digital audio signal output from the CD player is 44°1KHz, but the sampling frequency of the digital audio signal output from the BS tuner is 48KHz and 32KHz.
There are different types. There are two modes, A and B, for satellite broadcasting. Mode A allows long-term recording, is currently used for television audio, and is digitized at a sampling frequency of 32 to 7, and mode B is high-speed. This is because it corresponds to quality, and is currently used for music broadcasting and is digitized at a sampling frequency of 48kHz.The sampling frequency of digital audio signals from external DAT devices is the same as that from CD players and BS tuners. Since digital recording is possible, one of the three sampling frequencies mentioned above will be used.

Now, with a DAT device, there are cases where it is desired to fix the sampling frequency of music recorded on one tape to one. This is because if music with various sampling frequencies is recorded on a single tape, the quality of the sound will vary depending on the sampling frequency, causing a sense of discomfort or discomfort to the listener, or the DAT device may malfunction. This is because it may give rise to concerns that this may occur. That is, some users have a desire to record or edit music on one tape for each sampling frequency.

For this reason, for example, the sampling frequency is 48
If you want to record only KHz music (48KH)
z broadcasts only a small number of times), users manually record or timer recording according to the broadcast time.

Furthermore, in order to dub only the music at a desired sampling frequency from a recorded tape onto another tape, the user manually locates the beginning of the music at the sampling frequency and dubs the music.

<Problems to be Solved by the Invention> However, in the case of manual recording from satellite broadcasting or dubbing of music at a desired sampling frequency, the user has to record,
It is necessary to concentrate on dubbing editing, which requires a considerable amount of time and is troublesome.

In addition, in the case of timer recording, (1) it is unclear how much recording is necessary, so the tape is wasted, and (2) the L
, If the sending signal condition on the tuner side is unstable when recording starts at the set time, recording may be canceled or recording may not be possible.
Even if KHz music is recorded, it will still be 32K.
There is a problem that Hz music is also recorded.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a DAT device that can automatically record only music at a desired sampling frequency onto tape or dub and edit it.

<Means for Solving the Problems> In the present invention, the above problems are achieved by providing a means for specifying the sampling frequency of a digital audio signal to be digitally recorded on a magnetic tape, and a sampling frequency identification method for identifying the sampling frequency of a digital audio signal input manually. and a recording control means that enters a recording state when a digital audio signal of the specified sampling frequency is input in a recording standby state, and otherwise enters a recording standby state.

<Function> Specifies the sampling frequency of the digital audio signal to be digitally recorded on the magnetic tape, puts it into a recording pause state, identifies the sampling frequency of the input digital audio signal in this recording pause state, and selects the sampling frequency of the specified sampling frequency. When a digital audio signal is input, the system enters a recording state and records only music at a specified sampling frequency, and at other times enters a recording pause state.

<Embodiment> FIG. 1 is a block diagram of a system including a DAT device according to the present invention, in which 1 is a BS tuner, 2 is an external liquid MDA
3 is a CD player, 4 is a selector for selectively outputting a digital audio signal from a predetermined digital audio source, 5 is a DAT device according to the present invention (only the main parts are shown), and 11 is a digital I10. interface, 1
2 is a signal processing unit, 13 is an RF amplifier, 14 is a recording/reproducing head, 15 is a system controller, 16 is a tape running system,
A mechanical control unit for controlling the drum rotation system, etc., 17 is an operation panel equipped with various keys, switches, and a display unit, and 17a is a sampling frequency (48KHz, 44kHz) of a digital audio signal to be digitally recorded on a magnetic tape.
KHz, 32KH2), 17b is a recording key, and 17c is a pause key.

The digital E/○ interface 11 converts the input digital audio signal into a form that can be processed by the signal processing section of the DAT device, and outputs the converted signal.

It identifies and outputs the sampling frequency of the input digital audio signal, and its configuration is shown in Figure 2.
In the figure, 11a is a PLL circuit that generates a reproduced clock from input data, 11b is a reading circuit that reads digital data in synchronization with the reproduced clock, 11c is a demodulation circuit that demodulates modulated (bi-phase modulated) input data, 11d is an interface circuit that outputs audio signals, start IDs, and shortening IDs in a format that can be processed by the signal processing unit; 11e is an interface circuit that outputs sampling frequency information (
This is a sampling frequency identification circuit that identifies the sampling frequency of a digital audio signal based on channel bit (C bit) information. Incidentally, the sampling frequency may be identified by inputting the C-bit data to the system controller.

Although not shown, the PLL circuit 11a has a clock generator, an unlock detector, etc., and when a biphase mark modulated digital signal is input, the clock generator generates a clock signal synchronized with the biphase modulated data. C.L.
The unlock detecting section outputs an unlock state signal ULK when the PLL is unlocked.

The signal processing unit 12 adds an error correction code to the input digital audio signal during digital recording.

It is outputted along with a predetermined subcode to the recording/reproducing head 14 via the RF amplifier 13 and recorded on the magnetic tape.

FIG. 3 is a flowchart of a process for digitally recording music at a desired sampling frequency from satellite broadcasting, and the overall operation of FIG. 1 will be explained below in accordance with this flowchart.

Specify the desired sampling frequency with the switch 17a, and put the DAT device in the recording pause (recording standby) state using the recording key 17b and the pause key 17c (step 101).If the switch 17a is in the off position, recording will start. Input data is recorded regardless of the sampling frequency.

Thereafter, the system controller 15 determines whether the PLL is in the locked state based on the signal from the digital I10 interface 11 (step 102). If the PLL is in the unlocked state, it continues the recording pause state, and if it is in the locked state, the input digital audio is It is determined whether the sampling frequency of the signal matches the sampling frequency specified by switch 17a (step 103).

If the sampling frequency is not the specified sampling frequency, the recording pause state is continued, and if the sampling frequency is the specified sampling frequency, the tape running control is performed and recording is started (step 10).
4).

Thereafter, in parallel with recording, it is monitored whether the designated sampling frequency is detected (step 105).

Recording continues as long as it is detected, and when it is no longer detected, it enters the recording pause state and waits for music at the first sampling frequency to be input, and when it records to the end of the tape, it rewinds to the beginning of the tape and ends recording.

In addition, in the case of timer recording, when the set time comes, B
The S tuner and the DAT device are powered on, and then set to a recording pause state in step 101 to perform subsequent processing.

The above is a case of recording from satellite broadcasting, but similar processing is performed when dubbing and editing music at a desired sampling frequency from another DAT device.

<Effects of the Invention> According to the present invention, the sampling frequency of a digital audio signal to be digitally recorded on a magnetic tape is designated and the recording pause state is set.

In this recording pause state, the sampling frequency of the input digital audio signal is identified, and when the digital audio signal of the specified sampling frequency is input, it is set to recording mode and only the music of the specified sampling frequency is recorded, and the other Since it is configured to be in a recording pause state, by simply setting the sampling frequency, it is possible to automatically record only the music at the desired sampling frequency to tape or dubbing it.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a DATi device according to the present invention, and FIG. 2 is a block diagram of a digital I10 interface. FIG. 3 is a flowchart of the digital recording process of the present invention. 1...BS tuner 5...DAT device 11...Digital I10 interface 12...Signal processing unit 15...System controller 17a...Switch for specifying sampling frequency Patent applicant Alpine Corporation Agent
Patent Attorney *AI Senki Diagram 2

Claims (1)

[Claims] means for specifying the sampling frequency of a digital audio signal to be digitally recorded on a magnetic tape; sampling frequency identification means for identifying the sampling frequency of the input digital audio signal; and digital audio at the specified sampling frequency in a recording standby state. A DAT device characterized by having a recording control means that puts the device into a recording state when a signal is input, and puts it into a recording standby state at other times.