JPH0636451A - Digital compact cassette tape player - Google Patents

Abstract

PURPOSE:To exactly identify the kinds of cassettes regardless of a clogged hole by reproducing a tape when a detecting hole for identifying the cassette is in a closed state and comparing two signal components obtained in a high and a low frequency bands with a prescribed threshold value. CONSTITUTION:At the time of loading a cassette, the opening/closing of the detecting hole for identifying provided in the cassette is detected by an opening/ closing sensor for the detecting hole 19. When the detecting hole for identifying is identified to be in a closed state, the cassette is reproduced in an analog mode and a signal component in a comparatively low frequency band and a signal component in a comparatively high frequency band are extracted from the reproduced analog signal. Then, the levels of these two signal components are applied on a prescribed level deciding circuit, when a signal component in a low frequency band is smaller than a threshold value and a signal component in a high frequency band is larger than the threshold value, the cassette is changed to a digital reproduction and analog reproduction is performed at the time of the other decision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital compact cassette tape player, and more particularly, the cassette mounted in the digital compact cassette tape player is a digital compact cassette (hereinafter referred to as DCC) or an analog compact cassette. The present invention relates to a DCC tape player that performs a predetermined operation after accurately identifying whether or not it is (hereinafter, referred to as ACC).

[0002]

2. Description of the Related Art In recent years, a so-called DCC tape player for recording or reproducing digital audio data on a compact cassette tape by using a fixed head has been developed and is gradually being put on the market.

FIG. 5 is a block diagram showing an example of a fixed head used in the DCC tape player.

In FIG. 5, HD is a twin type fixed head, HD1 is a first fixed head, and HD2 is a second fixed head. TP is a DCC tape, SCA is an A sector in the DCC tape TP, and SCB is a B sector in the DCC tape TP.

The first fixed head HD1 and the second fixed head HD1
The fixed heads HD2 of each have 9 tracks (AU
X, 1 to 8) digital recording head DRH and 9 tracks (AUX, 1 to 8) digital reproducing head D
A PH and a left and right L and R analog reproducing head AH are provided, and the first and second fixed heads HD1 and HD2 are provided.
Is used for the forward travel (forward travel) and the backward travel (reverse travel) of the DCC tape TP.

In this case, the first and second fixed heads HD
1 and HD2 are for recording digital audio data on the DCC tape TP and for reproducing digital audio data recorded on the DCC tape TP.
The left and right L and R analog reproducing heads AH reproduce analog audio data recorded on the ACC tape. The length of the reproducing head DPH in the track width direction is equal to the first and second fixed heads HD1 and H2.
It is configured to be narrower than the length of the track D2 in the width direction, and is configured to be resistant to azimuth error. Further, among the 9 tracks (AUX, 1 to 8), track 1
Reference numerals 8 to 8 are used for recording and reproducing digital audio data, and the track AUX (auxiliary track) is used for recording and reproducing absolute time information, track number, lead-in, lead-out, reverse marker (reversal marker), and the like. It is a thing.

In the case of digital recording / reproduction, when the DCC tape TP is traveling forward (forward traveling), digital audio data is recorded in the A sector SCA or the same data is reproduced from the same sector SCA. On the other hand, when the DCC tape TP travels in the backward direction (travels in the reverse direction), digital audio data is recorded in the B sector SCB or the same data is reproduced from the sector SCB. In the case of analog reproduction, when the DCC tape TP travels forward (travels in the forward direction), analog audio data is reproduced from the B sector SCB, and the DCC tape TP travels in the backward travel (reverse direction). At this time, the analog audio data is reproduced from the A sector SCA.

FIG. 6 is a block diagram showing the arrangement of the detection holes provided in the DCC cassette half.

In FIG. 6, H1 is a detection hole for digital and analog identification, H2 is a detection hole for erroneous erasure prevention, H3 to H5 are detection holes for tape length determination, and H6 to H8 are preliminary detection holes.

The digital / analog discrimination detection hole H1 is for discriminating whether the cassette mounted in the DCC tape player is DCC or ACC. In the open (o) state, DCC is used. And the closed (c) state is identified as ACC. The erroneous erasure prevention detection hole H2 is for preventing erasure of recorded data by mistake, and recording is possible in the open (o) state and new recording is performed in the closed (c) state. Is blocked. The detection holes H3 to H5 for discriminating the tape length are used to discriminate the tape length as a whole, and various detection holes H3 to H5 are selected depending on the combination of the open (o) state and the closed (c) state of the three detection holes H3 to H5. The tape length is identified. FIG. 6 is an explanatory diagram showing a correspondence relationship between the open (o) state or the closed (c) state of the three detection holes H3 to H5 and the tape length. For example, all the three detection holes H3 to H5 are In the open (o) state, the tape thickness is 12 μm, and it is a 45-minute performance tape. Further, among the three detection holes H3 to H5, the detection holes H3, H
When 4 is in the open (o) state and the detection hole H5 is in the closed (c) state, it means that the tape thickness is 9 μm and that it is a 105-minute performance tape. In this case, in the combination of the open (o) state and the closed (c) state of the three detection holes H3 to H5, all the detection holes H3 to H5 are closed (c).
There is no combination to be in the state, and at least one detection hole is configured to be in the open (o) state. Note that the usage patterns of the preliminary detection holes H6 to H8 have not been determined yet, and are left for future operation.

According to the DCC standard, the well-known analog compact cassette (ACC) used so far.
It is essential to maintain compatibility with the CDC tape player, and when the cassette is mounted on the DCC tape player, the open / closed state of the detection hole H1 for digital and analog identification provided in the cassette is detected. As a result, whether the type of the cassette is DCC or ACC is identified, and the operation control peculiar to each type of cassette is performed based on the result of the identification.

By the way, the detection hole H1 for digital and analog identification provided in the cassette is in the open (o) state when the cassette is a DCC, but the detection hole H1 for digital and analog identification is not For example, when the cassette is practically closed (c) due to clogging of dust or the like or the detection sensor for detecting the open / closed state of the digital / analog identification detection hole H1 fails due to a cause, the cassette is Despite the DCC, there is a problem that the ACC is erroneously identified and the digital audio data cannot be normally recorded or reproduced normally.

In order to solve such a problem, when the applicant of the present invention mounts a cassette on a DCC tape player, the DCC tape player firstly detects the detection hole H1 for digital and analog identification. When the open / closed state is detected and the detection hole H1 for digital and analog identification is in the closed (c) state in this detection, that is, when it is detected that the cassette is ACC, then the When the open / closed state of the three detection holes H3 to H5 is detected and it is detected in this detection that at least one of the three detection holes H3 to H5 is in the open (o) state, the cassette is DCC. A DCC tape player designed to identify the above has already been proposed as Japanese Patent Application No. 4-115882.

[0014]

DCC according to the above-mentioned proposal
Although the tape player can solve the problem due to the clogging of the detection hole H1 for digital and analog identification or the failure of the detection sensor,
With the detection hole H1 for digital and analog identification,
The three detection holes H3 to H5 are clogged, not only the detection sensor of the digital and analog identification detection hole H1 but also the three detection holes H3 to H5.
If the detection sensor of is also broken at the same time,
After all, even though the cassette is DCC, ACC
There is a problem that the digital audio data cannot be normally recorded or reproduced normally because it is erroneously identified as ".

The present invention eliminates all of these problems, and its purpose is to prevent various detection holes including digital and analog identification detection holes from being clogged, or the above-mentioned various types. Another object of the present invention is to provide a DCC tape player capable of accurately identifying the type of cassette even if the sensor for detecting the detection hole is defective.

[0016]

In order to achieve the above object, the present invention detects the opening and closing of detection holes for digital and analog identification provided in the cassette when the cassette is mounted, and the cassette is for digital data. Or in a digital compact cassette tape player in which the required operation is performed after identifying whether it is for analog data,
When it is identified that the identification detection hole is closed, the cassette is analog-reproduced, the signal components of two frequency bands are extracted from the analog reproduction signal, and the extracted two frequency bands are extracted. The low frequency band signal component is below the threshold value, and only when it is determined that the high frequency band signal component is above the threshold value, the cassette is switched to digital playback, and the other In this case, a means for continuing analog reproduction is provided.

[0017]

The digital audio data recorded on the DCC tape, for example, the digital music signal has a transfer rate of 96 Kbit / sec / Track, whereas the analog audio data recorded on the ACC tape, For example, if the analog music signal is 2
Even if the signal component of 0 KHz is continuous, the transfer rate thereof is only 20 Kbit / sec / Track, and the values of these transfer rates have a large difference.

The present invention was carried out by paying attention to the difference in the value of the transfer rate, and two frequency bands f of high and low in the analog reproduced audio data (reproduction signal).
1, the signal components of f2 (where f1 <f2) are extracted,
Each extracted signal component is added to the level determination circuit, and each extracted signal component level is added to the threshold level Vt.
The level is compared with h, and the type of cassette is rechecked based on the comparison result.

That is, the DCC tape player first detects the opening and closing of the digital and analog identification detection holes H1 of the mounted cassette, and the detection detects that the identification detection holes H1 are closed (c). When it is identified that there is an analog reproduction of the tape of the cassette,
The reproduction signal obtained during this reproduction is extracted from the two frequency bands f1 and f2, and the extracted signal component levels are compared with the threshold level Vth. The comparison results are described below in the first to third sections. To see which one.

First, when the level of the signal component in the frequency band f1 is less than or equal to the threshold level Vth and the level of the signal component in the frequency band f2 is less than or equal to the threshold level Vth, the ACC Blank (non-recorded state) Judges that the tape is being reproduced in analog and maintains the analog reproduction state. Secondly, when the level of the signal component of the frequency band f1 is equal to or lower than the threshold level Vth and the level of the signal component of the frequency band f2 is equal to or higher than the threshold level Vth, DC
It is determined that the tape of C is being reproduced in analog, and the cassette is switched to digital reproduction. Thirdly, the level of the signal component of the frequency band f1 is equal to or higher than the threshold level Vth, and the level of the signal component of the frequency band f2 is also the threshold level Vt.
When h or more, it is determined that the ACC recorded tape is being reproduced in analog, and the analog reproduction state is maintained.

According to the above-mentioned means, since the type of the cassette is judged in two steps, the identification detection hole H1 or other detection holes H3 to H5 in the cassette may be clogged for some reason. , Or even if the detection sensor such as the detection hole H1 for identification or the other detection holes H3 to H5 fails, the type of the cassette can be accurately identified, and the identification can be performed by the DCC. Can be done without any changes to the standard.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a DCC tape player according to the present invention.

In FIG. 1, 11 is an input / output (I / O) interface for exchanging digital data and analog signals with an external audio device (not shown), and 12
Is a subband coding unit, 13 is a signal processing unit, 14 is a head amplifier, and 15 is a DCC or A
CC tape, 16 is a system controller that controls the entire DCC tape player, 17 is an operation unit of the DCC tape player, 18 is a tape running control unit, and 19 is a detection hole for detecting the open / closed state of the detection hole provided in the cassette half. An open / close sensor, 20 is an analog audio circuit.

Here, the I / O interface 11 is
An analog / digital (AD) converter 11a for converting an analog signal input from an external analog audio device into digital audio data, a digital I / O circuit 11b for exchanging digital data with the external digital audio device, and a tape. A digital / analog (DA) converter 11c for converting the reproduced digital audio data into an analog signal and supplying the analog signal to an external analog audio device.

Next, the subband coding unit 12
Comprises a sub-band filter 12a and a sub-band encoder / decoder 12b. Among them, the sub-band filter 12a is for recording and for reproducing, and for recording is orthogonal to the input digital audio data. The sub-band signals of 32 bands are finally generated and output by dividing the band into two bands of high and low by the mirror filter QMF, and the sub band signals of 32 bands to be input are reproduced for quadrature mirror filter QMF. In this way, the high and low bands are sequentially mixed to finally restore the digital audio data. The sub-band encoder / decoder 12b is composed of a recording encoder and a reproducing decoder. The recording encoder does not quantize sub-band signals below the masking threshold, and sub-signals above the masking threshold. Only the band signal is quantized, and the quantization is performed by assigning the quantization bit to the size of the difference between the sub-band level and the masking threshold level, and outputting the quantized data and the number of assigned bits. The reproduction decoder converts the input quantized data and the allocated number of bits into a subband signal of 32 bands by the operation opposite to the encoder operation and outputs the subband signal.

Next, the signal processing unit 13
Is a signal processing unit 13a and an error detection code addition / correction unit 1
3b and a modulation / demodulation unit 13c, in which the signal processing unit 13a performs addition / separation of system information and auxiliary information, and the error detection code addition / correction unit 1
3b is for adding an error detection code at the time of recording and detecting / correcting an error based on the error detection code at the time of reproduction. The modulation / demodulation unit 13c sets 1-bit 8-bit data at the time of recording.
The data is converted into 0-bit data and output, and 10-bit data is restored to 8-bit data during reproduction.

The head amplifier 14 is composed of a recording amplifier 14a, a reproducing amplifier 14b, a head 14c, an equalizer (not shown), and the like. Among them, the recording amplifier 14a outputs the amplified recording signal to the head 14c. 9 tracks for digital supply are provided, and a reproduction amplifier 14b amplifies a reproduction signal from the head 14c. 9 tracks for digital and 29 tracks for analog. It is provided for minutes.

Next, the system controller 16
Based on various key operations, predetermined reproduction control, recording control, pause control, etc. are executed, and the music number, playing time, etc. are displayed based on the auxiliary information recorded on the DCC tape 15, Information necessary for tape running control is supplied to the tape running controller 18. In addition, the system controller 16
Based on the detection signal input from the detection hole opening / closing sensor 19, the cassette mounted in the tape player and the tape length are identified.

Next, the tape running control section 18 runs the tape 15 at a fixed low speed at the time of recording or reproducing, and at the time of searching for a designated music number or the like, the tape 1
The tape running control is performed such that the tape 5 is run at a constant high speed.

Subsequently, the detection hole open / close sensor 19 detects the open / closed state of various detection holes H1 to H8 shown in FIG. 6 provided in the cassette half when the cassette is mounted on the tape player. A micropin switch that is turned on / off corresponding to the open / closed state of the detection holes H1 to H8 is provided in the detection holes H1 to H8 of the tape player body.
The structure is provided at a position corresponding to the position.

Next, the analog audio circuit 20 includes a selector 20a, a volume adjusting circuit (not shown), an amplifier and the like. The selector 20a receives a cassette identification signal CID output from the system controller 16,
Whether the cassette is a DCC or an ACC is identified, and as a result of the identification, the output of the reproduction amplifier 14b or the output of the DA converter 11c is selected and supplied to the speaker.

In this embodiment having the above-mentioned structure, the following operation is performed.

When recording digital data on the DCC tape 15, the digital audio data or analog audio signal to be recorded is input to the digital I / O circuit 11b or the AD converter 11a of the input / output interface 11 to input / output. Interface 11
Generate digital audio data at the output of. Next, this digital audio data is converted into digital quantized data or the like in the subband coding unit 12, and is supplied to the signal processing unit 13. Subsequently, the digital quantized data and the like are subjected to the signal processing as described above in the signal processing unit 13 and output as digital data. The head amplifier 14 amplifies the digital data supplied from the signal processing unit 13 with a recording amplifier 14a,
The nine recording heads DRH shown in FIG. 5 are energized to digitally record the digital data on the DCC tape 15.

On the other hand, when reproducing the digital data of the DCC tape 15, the nine reproducing heads DP shown in FIG. 5 are used.
The digital data read by H is amplified by the reproduction amplifier 14b, and the amplified digital data is supplied to the signal processing unit 13 via the equalizer. Next, the digital data is subjected to the signal processing as described above in the signal processing unit 13 and output as digital quantized data or the like. Next, the digital quantized data and the like are sent to the subband coding unit 1
At 2, the digital audio data is restored and supplied to the input / output interface 11. Furthermore, this digital audio data is input / output interface 1
It is output as digital audio data via one digital I / O circuit 11b, or is output as an analog audio signal via the DA converter 11c.

In addition to this, when reproducing the analog data of the ACC tape 15, the analog data read by the two left and right reproducing heads AH shown in FIG. 5 is amplified by the reproducing amplifier 14b, and the amplified analog is obtained. The data is supplied to the analog audio circuit 20 as an analog signal.
At this time, the selector 20 of the analog audio circuit 20
In a, the analog signal is supplied to the speaker in accordance with the instruction of the cassette identification signal CID output from the system controller 16.

Here, FIG. 2 is an explanatory view showing the positional relationship between the micro pin switch and the detection hole when the cassette is mounted in the tape player.

In FIG. 2, 21 is a cassette, 22 is a detection hole provided in the cassette half, and 23 is a micropin switch provided in the main body of the tape player. In the example of FIG. Detection hole H
3, H4, and H5 detect the tape length determining detection holes H3, H4, and H5 as the micro pin switch 23, respectively, and detect tape length determining micro pin switches M3 and M5.
4, M5 are shown.

By mounting the cassette, the tape length determining detection holes H3, H4, H5 are positioned on the tape length determining micro pin switches M3, M4, M5. When the tape length determination detection holes H3, H4, H5 are in the open state (o), the corresponding tape length determination micro pin switch M3,
When M4 and M5 do not operate and remain in the off state, while the tape length determination detection holes H3, H4, and H5 are in the closed state (c), the corresponding tape length determination micropin switch M3, M4 and M5 operate and are turned on. These micro pin switches M3, M4, M
The signal indicating the off state or the on state of 5 is obtained by the detection hole opening / closing sensor 19, and this signal is supplied to the system controller 16.

FIG. 3 is a circuit configuration diagram showing an example of an identification circuit for identifying the type of cassette in this embodiment. This identification circuit is arranged in the analog audio circuit 20, for example. It is a thing.

In FIG. 3, reference numeral 24 is a first bandpass filter for extracting a relatively low frequency band f1, 25 is a second bandpass filter for extracting a relatively high frequency band f2, and 26 is a level determination circuit. And others, Figure 1
The same components as those shown in are designated by the same reference numerals.

Next, FIG. 4 is a characteristic diagram showing an identification state of reproduction data in the identification circuit shown in FIG. 3, in which the horizontal axis represents frequency (Hz) and the vertical axis represents signal level (db).

The operation of identifying the type of cassette in this embodiment will be described below with reference to FIGS. 3 and 4.

First, the system controller 16
Through the detection hole opening / closing sensor 19, the open / closed state of the detection hole H1 for digital and analog identification of the mounted cassette half is identified. In this identification, the detection hole H1
If the system controller 16 determines that the cassette is a DCC, the system controller 16 supplies the cassette identification signal CID to the analog audio circuit 20, and performs digital recording / reproduction. The part is operated so that the digital data is recorded on the digital tape 15 or the digital data is reproduced from the digital tape 15. On the other hand, when it is detected that the detection hole H1 is in the closed state (c), the system controller 16 determines that the cassette is ACC, and then puts the tape 15 into the analog reproduction state and then the tape 15 The analog data is reproduced from.

Next, the reproduced analog data is
As shown in FIG. 4, the first band-pass filter 24 for extracting the relatively low frequency band f1 and the second band-pass filter 25 for extracting the relatively high frequency band f2 are supplied to the first and second Second bandpass filter 2
In Nos. 4 and 25, the first signal component of the relatively low frequency band f1 and the second signal component of the relatively high frequency band f2 are extracted from the reproduced data, and are extracted here. The first and second signal components are supplied to the level determination circuit 26, respectively. Subsequently, in the level determination circuit 26, the levels of the first and second signal components are compared with the threshold level Vth set in the level determination circuit 26 separately, and the comparison result is the system controller. 16 are supplied.

In this case, in the comparison result, the first signal component, that is, the characteristic curve b shown in FIG.
The level of the signal component in the relatively low frequency band f1 is less than or equal to the threshold level Vth, and the second
When the level of the signal component of, that is, the signal component of the relatively high frequency band f2 is also less than or equal to the threshold level Vth, the system controller 16 determines that the tape 15 on which the analog reproduction is performed is the analog tape 15. It is judged that the analog tape 15 is a blank (non-recording state) tape on which nothing is recorded, and thereafter the analog tape 15 is kept in the analog reproduction state, and the analog data is reproduced from the analog tape 15. Try to do it.

Next, in the comparison result, as shown by the characteristic curve a shown in FIG. 4, the level of the first signal component is less than or equal to the threshold level Vth, and
When the level of the second signal component is equal to or higher than the threshold level Vth, the system controller 16 determines that the analog data reproduced is almost the second signal component. It is judged that the tape 15 is digital data, that is, the tape 15 which has been subjected to the analog reproduction is actually the digital tape 15, and the analog reproduction state is immediately changed to the digital reproduction state. In addition to supplying to the audio circuit 20, a circuit portion for performing digital recording / reproduction is operated to record digital data on the digital tape 15 or reproduce digital data from the digital tape 15.

Further, in the comparison result, as shown by the characteristic curve c shown in FIG. 4, the level of the first signal component is not less than the threshold level Vth, and the level of the second signal component is also. When the threshold level is equal to or higher than the threshold level Vth, the system controller 16 causes the tape 15 on which the analog reproduction is performed.
Is an analog tape 15, and the analog tape 15 has analog audio data, that is,
Analog tape 15 on which analog music signals are recorded
It was judged that the analog tape 1
5 is maintained in the analog playback state, and analog tape 15
To reproduce analog data from.

By the way, even when the tape 15 is the analog tape 15 and an analog music signal is recorded on the analog tape 15 when the analog reproduction is performed, the analog music at the time of the reproduction is reproduced. When the signal hits the noise generating portion between one song and the next song, the levels of the first and second signal components obtained from the analog data at the time of reproduction show the characteristics shown in FIG. Since it becomes like the curve a, the system controller 1
No. 6 determines that the tape 15 being analog reproduced is the digital tape 15 even though the tape 15 being analog reproduced is the analog tape 15, and erroneously switches from the analog reproduction state to the digital reproduction state.

Therefore, in this embodiment, the system controller 16 maintains the digital reproduction state for a certain period of time after switching from the analog reproduction state to the digital reproduction state, and executes the servo operation during the digital reproduction. Then, when the servo operation can be executed, it is determined that the tape 15 is the regular digital tape 15, and thereafter, as described above, the cassette identification signal CID is supplied to the analog audio circuit 20. It suffices to activate a circuit portion for performing digital recording / reproduction to record digital data on the digital tape 15 or reproduce digital data from the digital tape 15. On the other hand, when the servo operation cannot be executed, It may be determined that the tape 15 is the analog tape 15 and the digital reproduction state is switched to the analog reproduction state again, and thereafter the analog data is reproduced from the analog tape 15.

As described above, according to the present embodiment, in the determination of the type of the mounted cassette, the determination based on the detection of the opening / closing of the detection hole H1 for digital / analog identification and the two frequency bands f1 during analog reproduction, Since the determinations based on the levels of the first and second signal components respectively belonging to f2 are also used, even if the identification detection holes H1 and other detection holes are clogged, or the identification Even if the detection sensor for detecting the detection hole H1 or other detection holes is out of order, the type of cassette can be accurately identified.

Further, according to this embodiment, during the analog reproduction, even if the levels of the first and second signal components of the reproduction signal are similar to those of the digital data, the subsequent servo operation Since the type of the cassette is determined again depending on whether or not it can be executed, the type of the cassette can be identified more accurately.

While the present invention has been described with reference to the embodiments, the present invention is not limited to the above-mentioned embodiments, and within the scope of the gist of the present invention. Needless to say, it can be appropriately modified.

[0054]

As described above, according to the present invention,
With respect to the mounted cassette, first, the opening / closing of the detection hole H1 for digital and analog identification is detected, and when it is determined that the detection hole H1 for identification is in the closed state (c) by this detection, the cassette The tape 15 is analog-reproduced, and the first signal component of the relatively low frequency band f1 and the second signal component of the relatively high frequency band f2 are extracted from the reproduced signal obtained at this time, and the extraction is performed. The levels of the first and second signal components are separately compared with the threshold level Vth, and whether the cassette is DCC or ACC based on the comparison result.
Therefore, even if the identification detection holes H1 and other detection holes are clogged for some reason, the identification detection holes H1 and other detection holes are detected. Even if the detection sensor for detecting a hole or the like is in an inoperable state (failure) for some reason, the type of cassette can be accurately identified.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a DCC tape player according to the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between a micro pin switch and a detection hole when a cassette is attached to a tape player.

FIG. 3 is a circuit configuration diagram showing an example of an identification circuit for identifying the cassette type in the present embodiment.

FIG. 4 is a characteristic diagram showing an identification state of reproduced data in the identification circuit shown in FIG.

FIG. 5 is a configuration diagram showing an example of a fixed head used in a DCC tape player.

FIG. 6 is a configuration diagram showing an arrangement state of detection holes provided in the cassette half of the DCC.

[Explanation of symbols]

 11 Input / Output (I / O) Interface 12 Sub-Band Coding Section 13 Signal Processing Section 14 Head Amplifier 15 DCC or ACC Tape 16 System Controller 17 DCC Tape Player Operation Section 18 Tape Travel Control Section 19 Detection Hole Open / Close Sensor 20 Analog Audio Circuit 21 cassette 22 detection hole provided in cassette half 23 micro pin switch 24 first bandpass filter 25 second bandpass filter 26 level determination circuit

Claims (2)

[Claims] 1. When a cassette is mounted, the required operation is performed after detecting the opening / closing of a detection hole for digital / analog identification provided in the cassette and identifying whether the cassette is for digital data or analog data. In a digital compact cassette tape player,
When it is identified that the identification detection hole is closed, the cassette is analog-reproduced, the signal components of two frequency bands are extracted from the analog reproduction signal, and the extracted two frequency bands are extracted. The low frequency band signal component is below the threshold value, and only when it is determined that the high frequency band signal component is above the threshold value, the cassette is switched to digital playback, and the other A digital compact cassette tape player that is characterized by continuing analog playback. 2. The digital reproduction is performed after the cassette is switched to the digital reproduction, the servo operation is executed during the digital reproduction, and when the servo operation cannot be executed, the cassette is switched to the analog reproduction again. The digital compact cassette tape player according to claim 1.