KR20020074545A - Apparatus of cassette tape type for recording and reproducing audio signal and audio system suitable thereof - Google Patents

Abstract

PURPOSE: A cassette tape type audio signal recording/reproducing device and an audio system proper to the device are provided to improve the reproduced sound quality by minimizing the loss of audio signals by transmitting the audio signal digitally. CONSTITUTION: A cassette tape type audio signal processing/reproducing device includes a control part(210) for setting audio signal transmitting mode between the device and an audio system as the device is inserted into the audio system, a memory part(215) for storing at least one digital audio file, a modulation part(220) for modulating the digital audio file read from the memory part as the digital audio signal transmitting mode is set by the control part, and a head part(201) for transmitting the digital audio signal transmitted from the modulation part to the audio system after modulating the digital audio signal to a magnetic signal.

Description

Apparatus of cassette tape type for recording and reproducing audio signal and audio system suitable according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette tape type audio signal recording and reproducing apparatus and an audio system suitable therefor, and more particularly, to a cassette tape type audio signal recording and reproducing apparatus capable of recording and reproducing digital audio signals and an audio system suitable for the same.

The cassette tape-type audio signal recording and reproducing apparatus is capable of compressing and recording and reproducing a large amount of music data such as an MP3 (MPEG Layer 3) player without degrading sound quality. It is implemented to record and play back audio by inserting like a cassette tape.

This makes it possible to listen to a large amount of high quality music data such as that provided by an MP3 player in a vehicle equipped with a cassette player or the like. In addition, when the corresponding audio system has a recording (REC) function, it is possible to compress and record the audio signal received through the audio system.

However, the presently proposed cassette tape type audio signal recording and reproducing apparatus is implemented in such a manner as to directly transmit an audio signal by directly contacting the magnetic head of the audio system and the magnetic head provided in the cassette tape type audio signal recording and reproducing apparatus. have. Referring to FIG. 1, the operation of a cassette tape type audio signal recording and reproducing apparatus currently proposed is as follows.

When the current operation mode is recognized as the playback mode through the playback sensor 101 included in the sensor unit 100, the controller 110 may store the digital audio file stored in a compressed form in the memory unit 115. The decoder 120 reads and transmits the data to the decoder 120. The decoder 120 restores the compressed digital audio file to the D / A converter 125. The D / A converter 125 converts the digital audio signal into an analog form and transmits the digital audio signal to the speaker 135 and the head 130, respectively. The head unit 130 converts the analog audio signal into a magnetic signal form and transmits the analog audio signal to the magnetic head of the audio system.

The speaker 135 allows the user to listen to the reproduced sound when the cassette tape type audio signal recording and reproducing apparatus is not inserted into the audio system. The reproducing sensor 101 is a cassette tape type audio signal recording and reproducing apparatus or a portion capable of detecting the pressing of the play button of the audio system when the cassette tape type audio recording and reproducing apparatus is inserted into the audio system (not shown). The playback button (not shown) mounted on the is mounted to a portion capable of detecting the pressing.

Meanwhile, if the current operation mode is recognized as the recording mode through the recording sensor 102 provided in the sensor unit 100, the control unit 110 receives the audio received through the head unit 130 or the microphone 150. The A / D converter 145 converts the signal into a digital form and transmits the signal to the encoder 140. The encoder 140 compresses the applied digital audio signal according to a predetermined compression rate and transmits it to the memory unit 115, and the memory unit 115 stores the file in the form of a file.

The recording sensor 102 is a part capable of detecting that the recording button of the audio system is pressed when the cassette tape type audio signal recording and reproducing apparatus is inserted into an audio system not shown as the reproducing sensor 101. In addition, the recording button (not shown) mounted on the cassette tape type audio signal recording and reproducing apparatus is mounted on a portion capable of detecting the pressing.

The FF (Fast Forward) sensor 103 and the REW (REWind) sensor 104 included in the sensor unit 100 are used for selection. That is, the FF sensor 103 detects the speed of the winding reel of the audio system, not shown, and generates a sensing output corresponding to the speed to the controller 110, and the REW sensor 104 is an audio system, not shown. Detect the speed of the rewind reel of to generate a detection output corresponding to the speed to the controller 110.

Therefore, the control unit 110 controls the omnidirectional search for the digital audio file stored in the memory unit 115 by the sensing output of the sensor FF 103, and by the sensing output of the sensor 104 for REW. The controller 110 controls the reverse search of the file to the currently reproduced digital audio.

At this time, however, the controller 110 searches for the music according to the control number of the FF button or the REW button of the audio system, not shown. For example, if you are playing the first digital audio file and you want to search for the sixth digital audio file, the FF button and the play button or the FF button and the stop button of the audio system are controlled six times. Should be. When searching for a digital audio file in the reverse direction, the buttons for REW and play, or for the REW and stop buttons are the digital audio file in the reverse direction based on the digital audio file currently playing. There is a disadvantage in that the control of digital audio file search is cumbersome since it must be controlled.

In addition, as the audio signal transmitted through the head portion is made in an analog form, transmission loss is generated due to sensitivity to noise, and thus, playback sound quality is degraded.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a cassette tape type audio signal recording and reproducing apparatus capable of transmitting digital audio signals between a cassette tape type audio signal recording and reproducing apparatus and an audio system and an audio system suitable therefor To provide.

Another object of the present invention is to provide a cassette tape type audio signal recording and reproducing apparatus and a suitable audio system, which are implemented to transmit a signal for controlling the operation of the cassette tape type audio signal recording and reproducing apparatus through the head portion.

In order to achieve the above objects, a cassette tape type audio signal recording and reproducing apparatus according to the present invention is a cassette tape type audio signal recording and reproducing apparatus which can be inserted and driven in an audio system having a structure such as a cassette player. A control unit for setting an audio signal transmission mode between the cassette tape type audio signal recording and reproducing apparatus and the audio system when the cassette tape type audio signal recording and reproducing apparatus is inserted into the system; A memory unit for storing at least one digital audio file; A modulator for modulating the digital audio file read from the memory unit when the cassette tape type audio signal recording and reproducing apparatus is set to the digital audio signal transmission mode by the control unit; And a head unit for converting the digital audio signal transmitted from the modulator into a magnetic signal and transmitting the magnetic signal to the audio system.

Further, the head portion preferably further has a function of receiving a control signal for controlling the function of the cassette tape type audio signal recording and reproducing apparatus from the audio system through a channel different from the digital audio signal.

In order to achieve the above objects, an audio system according to the present invention is an audio system having a structure such as a cassette player capable of driving a cassette tape type audio signal recording and reproducing apparatus. A head unit for receiving a modulated digital audio signal to be transmitted; A demodulator for demodulating a modulated digital audio signal transmitted from a head unit; A decoder for decoding the audio signal output from the demodulator; It is preferable to include an audio signal processing unit for converting the audio signal output from the decoder into an analog signal and output.

1 is a block diagram of a conventional cassette tape type audio signal recording and reproducing apparatus.

2 is a block diagram of a cassette tape type audio signal recording and reproducing apparatus according to the present invention.

3 is a block diagram of an audio system according to the present invention.

4 is a flowchart illustrating an operation of the apparatus illustrated in FIG. 2.

Fig. 5 is a flowchart showing the operation of the cassette tape type audio signal recording and reproducing apparatus when the continuous recording mode is requested.

FIG. 6 is a flowchart illustrating an operation of the audio system shown in FIG. 3.

FIG. 7 is an example of a screen displayed through the display unit illustrated in FIG. 3.

2 is a block diagram of a cassette tape type audio signal recording and reproducing apparatus 200 according to the present invention, which includes a head portion 201, a demodulation portion 205, a control portion 210, a memory portion 215, and a modulation portion ( 220 and the sensor unit 100, the decoder 120, the D / A converter 125, the A / D converter 135, the speaker 135, the encoder 140, and the microphone as shown in FIG. 1 ( 150).

The head unit 201 transmits a digital audio signal or transmits a digital audio signal to an appropriate audio system (not shown) when the operation mode of the cassette tape type audio signal recording and reproducing apparatus 200 is set to the digital audio signal transmission mode. Receives digital audio signals and control signals from a system (not shown). At this time, the digital audio signal and the control signal are transmitted through different channels. For example, the digital audio signal may be transmitted through the R-CH, and the control signal may be transmitted through the L-CH.

When the operation mode is set to an analog audio signal transmission mode, an analog audio signal is transmitted and received with the audio system (not shown). The audio system has a structure such as a cassette player, and has a function capable of driving the cassette tape type audio signal recording and reproducing apparatus 200 according to the present invention.

The demodulator 205 receives the digital audio signal and the control signal transmitted from the head unit 201 when the operation mode of the cassette tape type audio signal recording and reproducing apparatus 200 is set to the recording mode as well as the digital audio signal transmission mode. Demodulate according to the set method. The demodulated digital audio signal is transmitted to the memory unit 215, and the control signal is transmitted to the controller 210. The control signal may be transmitted through the demodulator 205 even in a mode other than a recording mode when the cassette tape type audio signal recording and reproducing apparatus 200 is set to the digital audio signal transmission mode. The demodulation method is the reverse of the modulation method performed in the audio system (not shown), and a demodulation method of a generally known digital audio signal modulation and demodulation method can be used.

The memory unit 215 is capable of reading and writing, and is configured to store one or more digital audio files.

The modulator 220 is configured to set the digital audio file transmitted from the memory unit 201 in the set manner when the operation mode of the cassette tape type audio signal recording and reproducing apparatus 200 is set to the reproduction mode while being the digital audio signal transmission mode. Modulate accordingly. The modulated digital audio signal is transmitted to the head portion 201.

As described with reference to FIG. 1, the controller 210 records a cassette tape-type audio signal by an output signal of the sensors 101 to 104 provided in the sensor unit 100 or a control signal input through the demodulator 205. And control the operation of the playback apparatus 200. Hereinafter, the operation of the controller 210 will be described in more detail with reference to FIG. 4.

That is, when the cassette tape type audio signal recording and reproducing apparatus 200 shown in FIG. 2 is inserted into an arbitrary audio system (not shown), the control unit 210 transmits an audio signal with a corresponding audio system. The signal for checking is transmitted to the corresponding audio system (not shown) (step 401). If the corresponding response signal is not received from the corresponding audio system (not shown), the controller 210 returns to the existing operation mode so that the cassette tape type audio signal recording and reproducing apparatus 200 operates in the same manner as before. It proceeds (step 403). As described above, an analog audio signal is transmitted between the cassette tape type audio signal recording and reproducing apparatus 200 and the corresponding audio system as described with reference to FIG. 1.

However, when a response signal corresponding thereto is received, the controller 210 sets the operation mode of the cassette tape type audio signal recording and reproducing apparatus 200 to the digital audio signal transmission mode (step 404). In operation 405, the controller 210 sets the automatic play mode to sequentially read the digital audio file stored in the memory unit 215 and transmit the digital audio file to the modulator 220. Accordingly, the modulator 220 modulates the applied digital audio file and transmits it to the head unit 201, and the head unit 201 converts the digital audio data into a magnetic signal to a corresponding audio system (not shown). Send it.

In this state in which the automatic playback mode is being performed, the controller 210 checks whether a control signal is received from a corresponding audio system (not shown) (step 406). If the control signal is not received as a result of the check, the control unit 210 returns to step 405 to continue the automatic playback mode.

However, if the control signal is received as a result of checking in step 406, it is checked whether the received control signal is a stop signal (step 407). If the result of the check is a stop signal, the operation of the cassette tape type audio signal recording and reproducing apparatus 200 is terminated. However, if it is not the stop signal, the corresponding function is performed in step 408.

Performing the corresponding function, for example, when the applied control signal requires REW, the controller 210 records the cassette tape-type audio signal to search the audio file in the reverse direction based on the digital audio file currently being reproduced. And control the operation of the playback apparatus 200. When the applied control signal requires FF, the controller 210 searches the audio file in all directions based on the digital audio file currently being reproduced. When the applied control signal requests REC, the controller 210 controls the cassette tape type audio signal recording and reproducing apparatus 200 to be operated in the REC mode. That is, the demodulator 205 controls the digital audio signal received from the audio system not shown through the head unit 205 to be demodulated, and the demodulated digital audio signal is recorded in the memory unit 215.

In addition, when the control signal received in step 406 is a signal for requesting a continuous recording (hereinafter, abbreviated as REC) mode, the controller 210 operates as shown in FIG. 5.

That is, it is checked whether the received control signal is always in the REC mode (step 501). As a result of the check, if the mode is not the REC mode, the process proceeds to the function execution mode corresponding to the received control signal (step 502).

However, if the check result shows that the recording mode is always, the control unit 210 sets the operation mode of the cassette tape type audio signal recording and reproducing apparatus 200 to the automatic REC mode in step 503. Accordingly, the digital audio signal received from the head portion 201 is transmitted to the memory portion 215 through the demodulation portion 205 and recorded in a predetermined storage location. In this way, while performing the recording mode, the controller 210 checks whether a normal REC control signal has been received (step 504). A normal REC control signal is a signal generated by controlling a REC function key included in an audio system not shown.

As a result of the check, if the normal REC control signal is received, the controller 210 proceeds to the normal REC mode in step 505. Accordingly, the cassette tape type audio signal recording and reproducing apparatus 200 stores the audio signal received before the normal REC control signal is applied to the memory unit 215.

However, if a normal REC control signal is not received as a result of the check, the controller 210 checks whether a predetermined time has elapsed in step 506. The predetermined time is for determining whether the information recorded in the memory unit 215 is present in the continuous REC mode.

As a result of the check, if the predetermined time has not elapsed, the process returns to step 504 to check whether the normal REC control signal has been received. However, if a predetermined time has elapsed as a result of the check, the digital audio signal recorded in the memory unit 215 from step 503 is erased in step 507. Next, in step 508, it is checked whether a signal for requesting to release the REC mode is received. As a result of the check, if a signal for requesting to release the continuous REC mode is received, the controller 210 terminates the continuous REC mode. However, if a signal for requesting to release the REC mode is not received as a result of the check, the process returns to step 503 and repeats the above-described process.

Meanwhile, an audio system suitable for the cassette tape type audio signal recording and reproducing apparatus 200 shown in FIG. 2 is configured like the audio system 300 shown in FIG.

3 is a block diagram of an audio system 300 suitable for a cassette tape type audio signal recording and reproducing apparatus 300 according to the present invention, which has a structure such as a cassette player, and includes a head portion 301 and a demodulation portion 305. , Decoder 310, audio signal processor 314, tuner 330, amplifier (hereinafter abbreviated as AMP) 335, analog / digital (A / D) converter 337, encoder 340, modulator ( 345, a control unit 350, a function key group 360, and a display unit 370.

The head part 301 is a magnetic head which contacts the head part 201 shown in FIG. 2 and transmits a magnetic signal. When the operation mode of the audio system 300 is a digital audio signal reproduction mode, the head part 201 is used. The digital audio signal is received from the digital audio signal, and the digital audio signal is transmitted to the head unit 201 in the recording mode. In addition, when a control signal for controlling the operation of the cassette tape type audio signal recording and reproducing apparatus 200 is generated, the head unit 301 transmits a control signal corresponding to the head unit 201.

However, when the operation mode is set to transmit the analog audio signal between the audio system 300 and the cassette tape type audio signal recording and reproducing apparatus 200, the head portion 301 is the head portion 201 and the analog audio signal only. Send and receive

The demodulator 305, the decoder 310, and the audio signal processor 314 are controlled and operated by the controller 360 in the digital audio signal reproduction mode. That is, when the playback key included in the function key group 360 is controlled, the controller 350 controls the demodulator 305 to demodulate the digital audio signal received through the head unit 301. The demodulation method is performed inversely with the modulator 220 of FIG. 2. The demodulated audio signal is transmitted to the decoder 310. The decoder 310 decodes the demodulated audio signal so that it can be restored to the original audio signal. The decoded audio signal is transmitted to the audio signal processor 314.

The audio signal processor 314 is composed of a digital / analog converter (hereinafter referred to as D / A) 315, an AMP 320, and a speaker 325, so that a user can listen to a decoded audio signal. Signal in a known manner.

On the other hand, when the audio system 300 and the cassette tape-type audio signal recording and reproducing apparatus 200 is set in the operation mode to transmit the analog audio signal received from the head unit 301 is the AMP 320 It is sent directly to) and signaled for user listening.

The tuner 330 receives an audio signal transmitted from the outside of the audio system 300 like an existing audio device. The AMP 335 amplifies the audio signal received from the tuner 330 by a predetermined value. The A / D converter 337 converts the amplified analog audio signal into a digital audio signal. The encoder 340 codes the digital audio signal to be compressed by a predetermined compression rate. The compression rate may be determined according to the structure of the memory unit 215 shown in FIG. 2. The coded audio signal is transmitted to the modulator 345. The modulator 345 modulates the coded audio signal according to a predetermined modulation scheme and transmits the coded audio signal to the head unit 301.

On the other hand, when the operation mode is set to transmit the analog audio signal between the audio system 300 and the cassette tape type audio signal recording and reproducing apparatus 200, the audio signal output from the AMP 335 is the head portion 301 Is directly transmitted to the head unit 201.

The function key group 360 is composed of function keys for controlling the functions of the audio system. For example, it may include a PLAY key, a REC key, a REW key, an FF key, a STOP key, a regular REC key, and the like.

The controller 350 controls the audio system 300 to drive the cassette tape type audio signal recording and reproducing apparatus 200. The operation of the controller 350 will be described in more detail with reference to FIG. 6 as follows.

First, in step 601 it is checked whether any cassette tape type audio signal recording and reproducing apparatus is inserted. As a result of the check, if inserted, it is checked in step 602 whether a signal for checking the audio signal transmission method with the audio system 300 is received from the corresponding cassette tape type audio signal recording and reproducing apparatus. If it is not checked, the process proceeds to the existing processing mode in step 603. This means that the cassette tape-type audio signal recording and reproducing apparatus currently inserted is not an apparatus 200 according to the present invention, but an apparatus for transmitting audio signals in a conventional analog form.

However, if a signal for checking a transmission method is received as a result of checking in step 602, the controller 350 indicates that the cassette tape type audio signal recording and reproducing apparatus inserted at this time is the apparatus 200 as shown in FIG. In step 603, a response signal preset in step 603 is transmitted. Accordingly, the response signal is transmitted to the head unit 201 shown in FIG. 2 through the modulator 345 and the head unit 301.

After transmitting the response signal, the controller 350 checks whether an audio signal is received through the head unit 301 (step 605). As a result of the check, when the audio signal is received, in step 606, the controller 350 controls the audio system 300 to perform a reproduction process on the received audio signal. That is, the digital audio signal received from the head unit 301 is converted into an electrical signal from the magnetic signal to be transmitted to the demodulator 305, and the demodulator 305 demodulates the applied digital audio signal, and the decoder ( In operation 310, the demodulated digital audio signal is decoded, and the audio signal processor 314 converts the decoded audio signal into an analog form and controls the decoded digital audio signal to be output in a form that a user can view.

Next, in operation 607, it is checked whether the function key is controlled in the function key group 360. As a result of the check, if the function key is not controlled, the flow returns to step 606 to continue the playback process. However, if the function key is controlled, the controller 350 checks whether the REC key is controlled in step 608.

As a result of the check, if the REC key is controlled, the playback processing is interrupted in step 609, and control is performed so that the REC function key information is sent. That is, when the REC function key information is output from the control unit 350, the control unit 350 controls the transmission to the head unit 201 through the modulator 345 and the head unit 301. At this time, the REC key always includes the REC key.

Then, the audio signal is transmitted to the cassette tape type audio signal recording and reproducing apparatus 200 (step 610). That is, the audio signal received through the tuner 330 is amplified by the AMP 335 to a predetermined value, the A / D converter 337 is converted into a digital audio signal, the encoder 340 is compressed, and the modulator In step 345, the audio signal is transmitted through the head unit 301 in the form of a digital signal.

Then, it is checked in step 611 whether the REC mode release key is controlled. As a result of the check, if the REC mode release key is not controlled, the flow returns to step 610 to control to continue the REC mode. However, if the REC mode release key is controlled, the process returns to step 607 to repeat the above-described process.

On the other hand, if the REC key is not controlled as a result of checking in step 608, the playback process is stopped in step 612, and the function key information is sent to the cassette tape type audio signal recording and reproducing apparatus 200. Accordingly, in the case of performing the FF control or the REW control on the cassette tape type audio signal recording and reproducing apparatus 200, it is possible to control only the FF key and the REW key without separately controlling the stop key or the playback key.

Next, in step 613, it is checked whether an audio signal has been received. As a result of the check, when the audio signal is received, the process returns to step 606 to repeat the above-described process. However, if no audio signal is received, it is checked in step 614 whether the cassette tape type audio signal recording and reproducing apparatus has been ejected. If it is not checked, it is returned to step 613. If it is ejected, however, the operation ends.

If no audio signal is received in step 605, the flow proceeds to step 614.

The display unit 370 is controlled by the control unit 350 to display the current operation state of the cassette tape-type audio signal recording and reproducing apparatus 200 so that a user can know the display unit 370. The display unit 370 may be a liquid crystal display. Can be configured. An example display is shown in FIG. 7.

The present invention is not limited to the above-described embodiments, and variations of the present invention can be made by those skilled in the art within the spirit of the present invention. Therefore, the scope of the claims in the present invention will not be defined within the scope of the detailed description, but will be limited to the claims below.

According to the present invention described above, by transmitting the audio signal transmitted through the head portion between the cassette tape-type audio signal recording and reproducing apparatus and the audio system in a digital form, it is possible to minimize the loss of the transmitted audio signal to improve the reproduced sound quality. have. Further, by transmitting a control signal for controlling the cassette tape type audio signal recording and reproducing apparatus through the head portion, there is an advantage that the function control of the cassette tape type audio signal recording and reproducing apparatus is easy. For example, when controlling FF or REW, conventionally, the PLAY or STOP key should be controlled after FF control as the reel drive is detected and performed. However, the audio signal recording and reproducing apparatus according to the present invention controls only the FF key or REW. Since the corresponding digital audio file can be searched by controlling the key, it is easier to control the function than the conventional cassette tape type audio signal recording and reproducing apparatus.

Claims (9)

In a cassette tape type audio signal recording and reproducing apparatus which can be inserted and driven in an audio system having a structure such as a cassette player, A control unit for setting an audio signal transmission mode between the cassette tape type audio signal recording and reproducing apparatus and the audio system when the cassette tape type audio signal recording and reproducing apparatus is inserted into the audio system; A memory unit for storing at least one digital audio file; A modulator for modulating the digital audio file read from the memory unit when the cassette tape type audio signal recording and reproducing apparatus is set to a digital audio signal transmission mode by the controller; And And a head unit for converting the digital audio signal transmitted from the modulator into a magnetic signal and transmitting the magnetic audio signal to the audio system. The apparatus of claim 1, wherein the head unit further includes a function of receiving a control signal for controlling a function of the cassette tape type audio signal recording and reproducing apparatus from the audio system through a channel different from the digital audio signal. Cassette tape type audio signal recording and reproducing apparatus. The audio recording and reproducing apparatus according to claim 2, wherein the cassette tape type audio signal recording and reproducing apparatus demodulates the control signal and transmits the demodulated signal to the control unit. And a demodulation unit for demodulating and transmitting the demodulation unit to the memory unit. 4. The digital recording apparatus of claim 3, wherein the controller records the digital audio signal transmitted from the demodulator in a predetermined time unit until a control signal for controlling a normal recording mode is received when the recording mode is a continuous recording mode. And repeatedly erasing the recorded digital audio signal. The recording and reproducing apparatus of claim 1, wherein the cassette tape type audio signal recording and reproducing apparatus A decoder which decodes to restore the digital audio file read from the memory unit when the cassette tape type audio signal recording and reproducing apparatus is set to an analog audio signal transmission mode by the controller; A D / A converter converting the digital audio signal transmitted from the decoder into an analog audio signal and transmitting the analog audio signal to the head unit; An A / D conversion unit for converting an analog audio signal transmitted from the head unit into a digital signal when the cassette tape type audio signal recording and reproducing apparatus is set to a recording mode in the analog audio signal transmission mode; And And an encoder for encoding the digital audio signal transmitted from the A / D converter to be compressed according to a predetermined compression ratio and transmitting the same to a memory unit. In an audio system having a structure such as a cassette player capable of driving a cassette tape type audio signal recording and reproducing apparatus, A head unit for receiving a modulated digital audio signal transmitted from the cassette tape type audio signal recording and reproducing apparatus; A demodulator for demodulating a modulated digital audio signal transmitted from the head unit; A decoder for decoding the audio signal output from the demodulator; And an audio signal processing unit converting the audio signal output from the decoder into an analog signal and outputting the analog signal. The method of claim 6, wherein the audio system, A group of function keys for controlling functions of the audio system and the cassette tape type audio signal recording and reproducing apparatus; When a function key for controlling a function of the cassette tape type audio signal recording and reproducing apparatus is controlled by using a function key included in the group of function keys, a corresponding control signal is transmitted through a channel different from the digital audio signal. The audio system further comprises a control unit for transmitting to the negative. The method of claim 7, wherein the audio system, A tuner for receiving an audio signal from the outside; An encoder for controlling the recording mode for the cassette tape type audio signal recording and reproducing apparatus, the encoder controlling the control unit to compress the audio signal received from the tuner according to a predetermined compression ratio; A modulator for modulating the compressed audio signal transmitted from the encoder and transmitting the modulated audio signal to the head unit; And the head unit transmits the digital audio signal and the control signal transmitted from the modulator in the recording mode to the cassette tape type audio signal recording and reproducing apparatus. 8. The audio system of claim 7, wherein the audio system further includes a display unit controlled by the control unit to display an operation state of the cassette tape type audio signal recording and reproducing apparatus.