JPH02247871A - Audio recorder for recording audio signal in analog system - Google Patents

Abstract

PURPOSE:To record an analog recording in high quality by providing an input terminal for a digital audio signal and a D/A converter and allowing the signal in a digital system as it is for transmission. CONSTITUTION:A digital signal is inputted from a CD player 2 to the input terminal B1 for the digital audio signal to be supplied to the D/A converter 5 via a memory 3 and a PLL demodulator 4. After the D/A conversion, analog audio signal L and R are generated via an LPF 6 to carry out the analog recording. By this method, deterioration of the audio signal in quality due to the line characteristic in the case of transmitting an analog signal to be input terminal is prevented, thus obtaining the audio recording capable of recording in high quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an audio recorder for recording audio signals in an analog format, having an input terminal for the audio signals to be recorded.

Conventional art cassette recorders for so-called audio signals operate in an analog recording system for audio signals.

In this case, the AF audio signal comes, for example via an input terminal, from another audio device or a microphone or, in so-called radio cassette recorders, from a tuner integrated into the audio recorder.

An AP audio signal, typically generated from a digital audio signal source such as a CD player, is also applied via a cable to the AN' input terminal of the audio recorder. In this case, due to the properties of the cable, for example due to its resistance, line inductance and line capacitance, the performance of the cable may be degraded, for example the bandwidth of the transmitted audio signal may be narrowed.

In this case, the very high quality of the audio signal generated from the digital source is degraded.

Problems to be Solved by the Invention It is an object of the present invention to provide a recording device in which no or only slight deterioration in the quality of the audio signal to be recorded by an audio recorder occurs. .

Means for Solving the Problem This problem is solved by the invention disclosed in claim 1.

The present invention is based on the following technical idea. The technical idea is that if the audio signal originates primarily from a digital audio signal source, it is advantageous to lead the transmission as far as possible in digital form to the recording stage. The cable parameters mentioned above should be maintained as long as they do not introduce bit errors in the digital audio signal.
The analog audio signal has no influence on the digital audio signal. For this reason, the audio signal is transmitted in digital form as far as possible, ie to the input of the audio recorder. Then, inside the audio recorder, the digital-to-analog converter converts the signal into an analog audio signal required for recording.

The audio recorder preferably has an output for digital audio signals. This output terminal is used to output the digital audio signal input to this recorder after appropriate signal processing, or to output the audio signal extracted by playback in the recorder to an analog analog signal.
Transmit after digital conversion. The recorder preferably has an input terminal and an output terminal for analog signals, in which case means are provided for switching between the processing of digital signals and the processing of analog signals.

Description of examples Next, embodiments of the present invention will be described using the drawings.

The illustrated analog recording format audio recorder 1 using a normal compact cassette is an analog,
It has the following terminals in total for digital input and output.

B1: Input terminal for digital audio signals to be recorded by recorder 1.

B2...Output terminal for an analog audio signal derived from the input audio signal (power coming from the playback path of the recorder) or the input audio signal.

B3... Input terminal for analog audio signals for recording or analog-to-digital conversion.

B4: Output terminal for a digital audio signal extracted from an incoming digital audio signal by signal processing.

B5: Output terminal for a digital audio signal taken out from the analog playback path or from an incoming analog audio signal.

B6: Output terminal of a CD player using digital audio signal system.

The various operating modes of the illustrated audio recorder 1 will now be described.

Recording of incoming digital signals.

The CD player 2 sends out a digital audio signal at its terminal B6, which signal is fed to the input terminal B1 of the audio recorder 1 via a rewriting sickle card.

The digital audio signal reaches the PLL demodulator 4 via the memory 3. The output signal of the demodulator 4 is supplied to a digital-to-analog converter 5. This converter generates two analog audio signals I, , R'i of a stereo audio signal via a low-pass filter 6. These signals are A in the left position of the changeover switch S1.
The signal reaches the P pre-emphasis circuit 7. This circuit advantageously performs signal pre-emphasis in Dolby or No-Icom formats. From here, the processed AP' audio signal R is supplied to an analog recording unit 8.

This unit includes a recording amplifier and a recording head for audio tape. The changeover switch S1 is switched to the left position by the manual operation button 9.

Recording of analog signals.

The analog AP audio signal is applied to the terminal B3 and reaches the recording unit 8 via the amplifier 10'jk and further via the changeover switch S1 switched to the right position.

Regeneration of analog signal output.

The AP audio signal reaches the output terminal B2 from the unit 8 via the circuit 7 and the right-hand position of the change-over switch S1 and the right-hand position of the change-over switch S2, where it is taken out as an analog AF audio signal I+IR.

Playback of digital audio signal output.

AP audio signal from changeover switch S1, R
is supplied to an analog-to-digital converter 11, where it is converted into a digital audio signal. This signal appears at output terminal B5 and can be supplied to a recording or reproducing device using digital signal processing.

Switching between analog and digital operation.

Switching between digital operation and analog operation using the aforementioned changeover switches S1 and B2 can also be performed automatically without using manual operation button /9. For this purpose, a correction variable U8 is generated when a digital signal is present in the demodulator 4. This U8 is the changeover switch S
1 and, if necessary, the other selector switch. Manual switching via button 9 is therefore no longer required.

Operation as digital to analog conversion.

When a digital audio signal is supplied to input terminal B1, this signal is sent via switch 82 to output terminal B2 for analog audio signals, instead of being digitally recorded or in addition to recording. supplied for playback or recording in any format.

Operation as an analog-to-digital converter.

When an analog audio signal is applied to the input terminal B6, this signal reaches the input side of the analog-to-digital converter 11 via the amplifier 10 and the right-hand position of the changeover switch S2.

This converter supplies a corresponding digital audio signal to an output terminal B5, for example for an I) AT recorder or other device in the form of digital audio signal processing. In this way, the audio recorder 1 is used as an analog-to-digital converter of audio signals, independently of recording.

Processing of digital audio signals.

The digital audio signal supplied via the input terminal B1ft reaches the signal processing circuit 12.

Here the digital signals are processed. For example, a new clock pulse or signal is generated, bit errors are detected and removed, or time errors are compensated for. This signal appears at the output terminal B4 as a processed signal. For example, the amplitude of the signal at terminal B4 is processed as follows. That is, terminal B4 is connected to a digital signal processing device such as another DAT recorder, receiver or
It is processed so that it is connected to a speaker installed at a remote location via a long cable.

As mentioned above, the present invention uses a changeover switch, which switches the analog recording device to the output side of the digital-to-analog converter or to the input terminal for analog AP audio signals as desired. be able to.

Further, a changeover switch is used, and the changeover switch can switch the analog output signal of the digital-to-analog converter to the output for analog AP audio signals.

Furthermore, the changeover switch can be automatically actuated by an identification signal derived from the signal indicating the presence of a digital signal.Furthermore, a PLL demodulator can be installed between the input terminal for the digital audio signal and the digital-to-analog converter. can be provided.

Furthermore, an output terminal for digital audio signals can be used, and an input terminal for digital audio signals can be connected to the output terminal via a signal processing circuit.

Furthermore, an output terminal for a digital audio signal can be used, and an analog playback path or an input terminal for an analog audio signal can be connected to the output terminal via an analog-to-digital converter.

Effects of the Invention According to the present invention, a recorder capable of high-quality analog recording is provided by providing an input terminal for digital audio signals and a D/A converter.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an analog audio recorder shown with a digital audio signal source. 1...Audio recorder, 2...CD player,
3...Storage device, 4...PLL demodulator, 5...D
A converter, 6... low pass filter, 7... pre-emphasis circuit, 8... analog recording unit,
9...Manual operation button, 10...Amplifier, 11...
・AD converter procedural amendment (method) Display of the case Heisei 1 Name of the invention Year Patent Application No. Audio recorder for recording audio signals in analog format 3° Relationship with the case Person making the amendment Patent applicant name Thomson On the shirt N stock 2 company 4゜

Claims (1)

[Claims] 1. In an audio recorder that records audio signals in an analog manner and has an input terminal for an audio signal to be recorded, the recorder (1) is provided with an input terminal (B1) for a digital audio signal, and the input terminal is further provided with an input terminal (B1) for a digital audio signal. An audio recorder for recording audio signals in an analog format, characterized in that a digital-to-analog converter (5) is connected.